Whilst the MR2 Roadster has very few flaws as either a fun cheap sports car or as a precision tool to hit the track with, there is one thing that we as a Club feel every owner should be aware of, and that is the pre-catalytic converters (or pre-cats for short). There have been a huge amount of questions on here since the forum began regarding these, and this thread is here to hopefully answer any and all questions that have cropped up about the pre-cats, as well as dispel some myths about them.
*Please note: The Club neither encourages nor advocates the interference with emissions equipment on any motor vehicle, and we take no responsibility for any action taken by any person as a result of reading this article. All text and pictures here are for information purposes only.*What is a pre-cat?[/u]To put it quite simply, the pre-cats sit before the main catalytic converter in the exhaust system and help to keep the harmful emissions as low as possible for a short period after you start the car up. Of course, there is slightly more to it than that...
The main catalytic converter in the Mk3 works best at converting the harmful compounds contained within the exhaust gas at high temperatures: However, since the engine takes a while to heat up to it's optimum running temperature, there is a time when a great deal of harmful emissions are allowed to simply pass straight through the cat and are dispersed into the air. Toyota obviously wanted to keep these emissions to an absolute minimum to enable the car to be classed as a ULEV (Ultra Low Emissions Vehicle) to allow the Mk3 to be sold in California (they have practically the most stringent rules on car emissions anywhere in the world there!), so between the engine and main cat they placed two pre-cats contained within the main manifold itself. The manifold itself looks like this:
(http://www.spydermagazine.com/2003/Nov/ppe/image012.jpg)
The four headers run into the two chambers containing the pre-cats, and then they're passed onto the main cat to let it do its job. The pre-cats are made from a ceramic material, which whilst excellent at absorbing the noxious gasses at low temperatures, is also highly brittle...
Why are we worried about them?As stated above, the pre-cats themselves are not the strongest material known to man, and they have been known to break down and enter the engine, causing serious damage to the internals. When this sort of damage has occurred, you are almost certainly looking at needing a new engine.
Woah, wait a minute! How can the pre-cat get back into the engine: Surely the exhaust flow pushes it all out?True to a certain extent, but here's the clever bit...
The 1ZZ-FE engine (Toyota's designation for the engine inside the MR2 Roadster) is a very clever piece of kit, and arguably its main party piece is the VVTi, or Variable Valve Timing Intelligent. This increases engine response all over the rev range by altering the timing of the cams, allowing for differing amounts of valve overlap in order to give great low-down torque as well as good top-end power. The 1ZZ also uses it's VVT to perform EGR (Exhaust Gas Recirculation) functions without the aid of a specific valve like other cars. Under certain operating conditions (usually steady cruise) the cams are timed to scavenge some exhaust gas back into the cylinders, as a way of reducing the high hydrocarbon emissions that modern petrol engines generate at certain times.
Unfortunately, when you combine this with some very sharp ceramic pre-cat particles, you can imagine what happens: The pre-cats start breaking down, and get dropped into the main cat which then causes excessive pressure, leading to oil blow-by in the engine. When the VVTi kicks in, the pre-cats are sucked back in and scratch and score the cylinder walls, leading to more oil passing by the piston rings and being burnt off without you even realising it. No oil in an engine leads to massive failure as every moving part grinds against metal, and in short you end up with a practically useless engine. When this happens the situation is compounded by the fact that hot oil is now allowed to drip directly onto the pre-cats and break them down even quicker, which in turn allows large chunks to block the main cat even more, which then stops any smaller pre-cat material escaping at all and sucks even more back into the engine to cause even more damage... A vicious circle of the very worst kind.
Some common symptoms of pre-cat failure are extreme oil loss, very noticeable lack of power all the way through the rev range, and horrible noises coming from your engine bay. Essentially, if you've got any of these problems and they are
directly related to pre-cat loss, then it's too late. Even the oil warning light won't save you here, as by the time it comes on there's almost zero oil left in the engine anyway.
For more information on how an engine works in general, please click here for a link to HowStuffWorks.com (http://auto.howstuffworks.com/engine.htm)But I've read elsewhere that the pre-cats themselves are fine, it the piston rings which are the weakness...This is where we come across a real conundrum, and a question to which no-one has a definitive answer. It's true that on very early MK3s there was a known problem with the piston rings themselves on a 1ZZ, and Toyota issued a technical document to the dealers around the world stating as such. They also changed the design of the piston rings for the facelift version of the Roadster, which became available in 2003.
Now whether it's a case of the piston rings failing, oil dripping onto the pre-cats and breaking them up, or the pre-cats self destructing and taking the piston rings with them, we just don't know. All we do know for certain is that whilst you can't take the piston rings out of the engine, you can remove the pre-cats from the manifold. No pre-cats = Nothing to get sucked back into the engine.
Okay, so the pre-cats are obviously a bad thing, but what can I do about it? Is there any way to tell if they're okay on my car?There is only one sure way of telling, and that it to remove the entire manifold and check both the top and bottoms of the pre-cats for any signs of damage. This is the only 100% way.
I'm not very mechanically minded, so is there another way? Even if it's not 100%?Yup, and this is the way 99% of people do it (myself included). It's very simple, and requires nothing more than a 22mm O2 sensor removal socket (Available from here for one, but you can get them at many other places as well, this is just an example (http://www.gendan.co.uk/product_DR55540.html)), a can of PlusGas or similar penetrating oil (WD40 will do at a push, but it's a lot easier with the PlusGas), and a torch.
(http://www.spydermagazine.com/2003/Nov/ppe/image006.jpg)
The picture above shows the heatshield which covers the manifold itself, and is how your car looks when you open the engine bay. Coming out of either side of the heatshield are the O2 sensors, which need to be removed to see the pre-cats from the top only.
1. Get the engine nice and warm first, it'll make this job a lot easier!
2. Spray the PlusGas liberally onto the joint where the O2 sensor meets the manifold. Leave for 10 minutes, then spray it again. You cannot use enough of this stuff, trust me! Don't worry about the steam coming off; it's not doing anything any harm.
3.
Being very careful not to burn yourself on the heat shield, use the O2 socket to remove the sensors, Unplug them first from the plastic clip (it's a simple push-tab-and-release connection), and make sure you turn them anti-clockwise. If you have an older vehicle, you may find that these are very stubborn, but do persevere and don't be afraid to give it a little elbow-grease!
4. Pull the sensor out of the socket and place carefully on the floor, away from your feet. You don't really want to tread on it now you've done the hard part, do you?!
5. Take the torch and shine it into the holes. You're looking for a completely solid honeycomb matrix with no cracks or large holes in it, like this:
(http://www.spydermagazine.com/files/GSBprecat1.jpg)
6. When you've finished checking (and hopefully found that they're still intact), simply screw the O2 sensor back in and nip it up with the socket. Oh, and you may want to plug it back in too. s:wink: :wink: s:wink:
My pre-cats look fine! I'm safe! *dances*Not quite: They're still very fragile, and remember you can't see the bottom of the matrix from that angle either. All this means is that your engine is still fine and you're not in any immediate danger of the pre-cats failing.
Oh, okay. So what's the next step then?The only 100% sure way to protect your engine is total removal of the pre-cats from the manifold. This isn't a particularly hard job, but it is more involved than simply removing the sensors.
Below is a complete set of instructions to do this, written by Grant (GSB). Do it his way and you won't go far wrong.
Many thanks to Grant for producing such a wonderful and complete guide to this.
Quote from: GSBHeres how I removed the cats...
Note: Clearly, neither I nor MR2-ROC can condone you ripping lumps of emmisions control equipment out of your car. Its safe to say the the warranty on my manifold at least and probably my main cat as well have now been well and truly voided, so the same will go for you. Basically, if you decide to go down this route as I have, you're on your own... On the plus side, if its not in there, it cant break. s:wink: :wink: s:wink:
Toolkit required
Trolley Jack
Axle Stands
10mm spanner
10mm socket on 6" extesnion
12mm spanner
12mm socket and various extensions
14mm socket
Hammer
Vice
Long flat bladed screwdriver
High pressure water or air supply
Large vocabulary of swear words
In order to remove the precats, you first have to remove the exhaust manifold from the car, Care should be taken to apply penetrating oil to the various nuts and bolts some time before undoing them
1/ Jack up the rear of the car and place on axle stands.
2/ Remove the splash guard from under the rear bumper
3/ Remove 3 bolts from the forward splash guard to let it hang down.
4/ Remove the 3 14mm nuts that secure the main cat pipe to the manifold
In the engine bay;
5/ Using a 22mm O2 sensor socket, remove the 2 O2 sensors from the manifold.
6/ Remove the 4 bolts securing the manifold upper heat shield
7/ Remove the 2 bolts that secure the lower part of the manifold to the engine block. These are 'behind' the manifold and not readily visible. ! of them is 12mm, the other 14mm.
8/ Remove the 5 nuts securing the manifold to the cylinder head.
The manifold can now be lifted out of the top of the engine bay.
Decatting the precats...
Actually getting the precats out is pretty simple, here's what mine looked like from above and below before I started, you can see some of the degradation thats taken place in the first photo:
(http://www.spydermagazine.com/files/GSBprecat1.jpg)
(http://www.spydermagazine.com/files/GSBprecat2.jpg)
And here are the surgeons tools: s:wink: :wink: s:wink:
(http://www.spydermagazine.com/files/GSBprecat8.jpg)
Removal is simply a case of attacking the precat matrix with hammer and screwdriver until its broken up into lumps small enough to be able to get them out through the lower exhaust port. The ceramic material gives up very easily, it only takes 1 or 2 taps on the screwdriver to do this... s:shock: :shock: s:shock:
(http://www.spydermagazine.com/files/GSBprecat5.jpg)
After digging around for a while you will also expose the glass fibre that surrounds and supports the cat matrix, this has to come out too.
(http://www.spydermagazine.com/files/GSBprecat4.jpg)
Once out you'll have a big pile of very useless, but rather expensive catalytic material left over. I beleive some places do recycle this stuff to reclaim the precious metal content, so if your now feeling guilty about your effect on the environment, this could be a way to ease your concience s:wink: :wink: s:wink:
(http://www.spydermagazine.com/files/GSBprecat6.jpg)
Once its all out, you'll be left with an empty manifiold like this;
(http://www.spydermagazine.com/files/GSBprecat7.jpg)
You now need to clean it, as there is still an awful lot of potentially damaging dust and particles left inside. I would recommend high pressure water like a jet wash or an airline for this, as an chemical residue from solvent cleaners may have a damaging effect on the O2 sensors.
Once clean and dry, re-building is simple the reverse of the process used to take the manifold out in the first place.
Happily, I've not noticed any increase in noise level from removing these. Performance certainly isnt any worse, and in fact the car may have benefitted in the form of slightly increased torque, but I cant say for sure... What is certain though, is that the pre-cats are going to have a hard time damaging my engine from the workshop bin, and I'm a lot happier now that these ticking time bombs are not a problem...MOT tests wont be a problem, as I still have the main cat in place, which is more than capable of doing the work. I dont have a ULEV car anymore, but I do have one that with a bit of luck will last a bit longer.
Alternatively, some owners have found some garages that will do this for you, for a price obviously.
HERE IS A LIST OF KNOWN COMPANIES THAT WILL DO THIS WORK (http://www.mr2roc.org/phpBB2/viewtopic.php?t=11137)Please note the above list is not total: If you know somewhere that offers this service, then go ahead and post it up for fellow members to know about!
Hmm, I don't really fancy doing this to my car: Are there any other alternatives?Certainly, although they obviously cost a bit more. The obvious way is to change the stock manifold for an aftermarket item, and you can't really go wrong here as there are no aftermarket manifolds that include the pre-cats. The cheaper options are to buy a performance manifold from either TRD (Toyota's own tuning brand), PPE or Top Secret. Other manifolds are available, but these are the most common ones and should cost you in the region of £500 each. These manifolds also come with the benefit of extra performance, however don't forget to inform your insurance company if you fit one!
Another alternative is Che's Manifold, which has been designed and manufactured by a chap over in the US who posts on SpyderChat. (Click here for the thread on SC) (http://www.spyderchat.com/phpBB2/viewtopic.php?t=29770). This hasn't been dyno tested to prove any performance gains, but then again it's by far the cheapest way to get a new pre-cat free manifold.
There is another way to replace your manifold, but it does get considerably more expensive... Turbo conversion. The Hass, C2, PE and Top Secret kits do not include any pre-cats in their design, whilst the TTE kit's pre-cats are of the metal type, and are far more resistant to ever breaking. Far more resistant as in 'will not unless you attack them for a good few hours with a large hammer'. Obviously this isn't really a solution for most people due to the cost involved, but it's a fair point to mention.
Okay, so I've decided to remove my pre-cats the old fashioned way. What about the MOT? Will I still pass it?Whilst we cannot say for 100% certainty that your car will pass MOT after pre-cat removal, we do know of a good few members on here whose cars have passed MOT with flying colours, and some more than once. As long as the engine is nice and warm before the test commences, the stock cat is more than capable of filtering out any nasties from the exhaust gas. As stated above, the pre-cats only work for a short period from cold anyway.
I've got a very low-mileage car, does any of this really apply to me?This information should be heeded by every MR2 Roadster owner, regardless of model year/mileage done. To quote my own personal experience, on my 2003 Roadster (after the piston ring re-design), I checked my pre-cats after just 15k miles, and they had started to disintegrate. Luckily I caught them in time, but this just goes to show that it's not only high mileage/older cars that can suffer from pre-cat breakdown.
Granted, there is evidence that this happens more often on older cars, and as a general rule of thumb it seems that most cases occur around 30-40k miles. However, that doesn't mean that you should be waiting that long before you start checking the pre-cats: Remember, as soon as they start to go then you've more or less had it, and by the time you notice the symptoms it's usually too late...
As a footnote, when I discovered my own pre-cats had started to degrade, I made Toyota replace my whole manifold for a new one. After 3 days of it being on I gutted it, although not before noticing that the brand new pre-cats had signs of damage to them as well. I'm not trying to state anything in particular here, merely making an observation.
Argh, I've caught it too late! My pre-cats are gone and my engine is done for, what do I do from here?!First off, don't panic! Although the Roadster is a relatively rare vehicle in the Toyota line-up, the engine it uses isn't: It's found in the Celica, Avensis and the Corolla, so if you need to source a new engine it's not going to be a hard job finding one and at a decent price (from £500 for a high-mileage one to £1000+ for a slightly more recent one). All engines aren't 100% identical though: You may need different wiring parts and engine mounts fabricating, but any garage worth it's salt should be able to do this for you.
The other alternative is to repair your old engine. To do this, you will need:
New main catalytic converter
New manifold (stock or aftermarket)
...parts-wise at the very minimum, along with a full engine rebuild to sort out whatever damage may have been caused (not all engines will break in exactly the same way, due to the normal fluctuations in the building process), although you can certainly include cylinder re-lining as part of that.
Total cost of this will vary from garage-to-garage, but you don't need to go to a Toyota main dealer to do this: All you really need is a garage you can trust, and there's literally hundreds of quality garages that can do this kind of work all over the country. Ask around here, your friends, work colleagues, and any other places you can think of to get a recommendation for you. Remember, it's your pride and joy we're talking about here, so the cheapest place might not necessarily be the best.
*NOTE* If this happens within your car's warranty period (i.e. first three years), then you need to take your car
straight back to your Toyota dealer. The law is on your side in this, so don't be afraid to use it.
So there you go, that's just about everything you need to know regarding the Roadster and the pre-cats. This thread isn't meant to scare you in any way or put you off owning what is one of the finest driver's cars ever built, it's just information and a way of combining the knowledge contained in this forum into a single thread to save you all searching. Think about how many Roadsters Toyota have built, and how many pre-cat related engine deaths we know of... It's a tiny fraction. Toyota build hugely reliable cars, and the MR2 is no exception: The pre-cat issues mentioned above are merely what we as enthusiasts have noted over a few years since the release of the car, and in no way are any slight on Toyota's ability to mass-produce an affordable convertible. Every car ever built has issues, and we are fortunate that the Roadster has so little to worry about. We just want you to be able to enjoy many years of care-free ownership, and every mile in this little car is one that should be enjoyed with a smile on your face.
Excellent job Dan, for a Vauxhall man s:wink: :wink: s:wink:
Just one thing to add to GSB's "how to" post, a drill with a long bit (maybe one of those wide wiggly wood ones - there must be a technical name) are very good at breaking up the cats for removal.
Appreciate all the effort that has gone into writing that s:bowdown: :bowdown: s:bowdown:
Something I will definently do on my '2
Cheers s:) :) s:)
Quote from: "roger"Excellent job Dan, for a Vauxhall man s:wink: :wink: s:wink:
Just one thing to add to GSB's "how to" post, a drill with a long bit (maybe one of those wide wiggly wood ones - there must be a technical name) are very good at breaking up the cats for removal.
a long masonary bit is wgat we used, I wouldn't use a wood boit on ceramic
Quote from: "markiii"I wouldn't use a wood bit on ceramic
I did on my second pre-cat removal (as I said one of those wide ones 1/2"+), it worked a treat and didn't seem to harm the bit at all.
either is fine, whilst the ceramics is abrasive as hell the wood bit with cut it with no worries, the precats are soft as butter. Only difference at the damage end of a wood and masonery bit is the cutting angle but on a substance like this it wont matter which one you use
Sorry if this has been mentioined elsewhere, but does anyone know the official Toyota company line on Pre cats?
Do they acknowledge the problem....
what happens after 3 years warranty...
Do they check pre cats on servicing etc?
Not worried yet..got year left on warranty...but it may influence an extended warranty purchase etc.
Many thanks
the official line is "what problem?"
they have never acknoledged the problem even with all the press coverage. They just choose to turn a blind eye and hope it goes away, however if you have a warranty then they will of course repair any issues whilst that warranty stands
Thanks for the info.
Extended warranty may just be worth it...depending on what they charge s:) :) s:)
If you're only going to take out the extended warranty for the pre-cats, I wouldn't bother. Rip them out and save yourself the money.
If you want it for other reasons (i.e. to protect against anything else non pre-cat related), then it's probably worth it.
Hi All,
Newby here so please be gental.
Before buying my 2 in feb (best car I've had since a homologated celica gt4x4) I did a lot of reserch and read about the pre-cat failures on the mr2 owners club web site, but in a thread it stated that the problem was fixed in 2002 and only applied to older cars so I was reasured when I got my 04 mr2. However having read through the majority of the stuff on this site I can't find any reference as to whether the pre-cat problem has been fixed!
Help!
Luckily I've still got 12months waranty left. Do I need to worry, car only done 15k, having it unichiped this week and I don't drive like vicar!
Definately not 100% fixed, as I said above my 2003 post-facelift car had pre-cats that had just started to go.
Personally, I feel it's a check thet EVERY mk3 owner should do, regardless of the age of the car. Check them, and then if they've started to go claim for a new manifold under warranty, like I did.
And welcome to the club! s:D :D s:D
Bad news for those who thought that new cars would be ok:
m http://www.spyderchat.com/phpBB2/viewtopic.php?t=35341 (http://www.spyderchat.com/phpBB2/viewtopic.php?t=35341) m
Quote from: "Tem"Bad news for those who thought that new cars would be ok:
m http://www.spyderchat.com/phpBB2/viewtopic.php?t=35341 (http://www.spyderchat.com/phpBB2/viewtopic.php?t=35341) m
Yes no point in waiting for the warrenty to run out; mine were out at after just 1 year s:wink: :wink: s:wink:
Quote from: "heathstimpson"Yes no point in waiting for the warrenty to run out; mine were out at after just 1 year s:wink: :wink: s:wink:
Even before that, thanks to Mark's badgering. Glad he did now s:D :D s:D
Newby here, so please correct me if I am wrong.
But I thought that all Uk spec cars have three oxygen sensors, two before the pre cats and one after the pre cats. So won't cutting out all the pre cat material put on the engine management light??
I know that all MR-S (imports) only have two sensors before the pre cats. So they can't be affected.
your right about the O2 sensors on UK and Jap spec cars, however your not removeing the main cat, just the pre-cats, so no it wont bring the CEL light on
great info on this
1 question- i am planning on purchasing a mk 3 2 some time soon. however, i doubt i will be able to check the pre cat until i have purchased the car (and prob driven it home!). perhaps only a fellow member on here would let it.
this being the case, does a degrading pre-cat slowly damage the engine (meaning that unless you check it the engine could be part damaged and so symptomless)
OR does the pre cat pretty much knacker the engine in 1 dreadful drive meaning that you can take a chance without inspecion and get it sorted pretty quick after purchasing>????
in truth it can be either
Quote from: "markiii"in truth it can be either
hmmmmm pitty, are the majority slowly damaging the engine or majority damage quickly?
im after facelift 03 on a budget with hard top so will prob bee looking at high mileage one s:? :? s:?
good news is that post 03 are statistaclly less likely to be a problem
in your shoes I'd check the oil level, check the precats (by removing teh 02 sensors)
and if there ok, I wouldn't worry for teh drive home.
then gut them ASAP
As mentioned in another of my posts i've just removed my pre-cats (huge weight off my mind) has anyone had any probs after removing them??
I've noticed that this hasn't been asked before so i'm assuming not.
All i have noticed is my '2' now sounds like its blowing abit at low revs but i'm putting that down to change in sound due to removal or needing new exhaust seals on the manifold as we used the old ones s:oops: :oops: s:oops: because they were in good condition (and it was a sunday so couldn't get any and forgot before hand) so just covered them in sealer and popped em back in!
Has anyone else got that blowing sound since removal??
To be honest, this is the 1 thing putting me off getting an mr2... how am i going to know, that the engine isnt shot before i even start?
grrr s:evil: :evil: s:evil:
The same arguement could be said for any car with "known" faults, having said that failure rate is low, and there is still the unanswered question whether pre-cats are the cause or the result of a problem.
To answer your question:-
1. Buy an 03+
2. Inspect pre-cats before you buy
3. Take them out after you buy
4. Have a warranty with the car. If its shot when you buy, it'll be gone well within 3 months!
5. Warranty Direct do 12 months for around £200 depending on mileage for use after garage warranty ends.
Quote from: "roger"The same arguement could be said for any car with "known" faults, having said that failure rate is low, and there is still the unanswered question whether pre-cats are the cause or the result of a problem.
To answer your question:-
1. Buy an 03+
2. Inspect pre-cats before you buy
3. Take them out after you buy
4. Have a warranty with the car. If its shot when you buy, it'll be gone well within 3 months!
5. Warranty Direct do 12 months for around £200 depending on mileage for use after garage warranty ends.
Roger, im fairly sure Warranty direct does not cover piston ring failure, which would pretty much give them a get out of jail free card i would have thought.
Quote from: "nelix"Roger, I'm fairly sure Warranty direct does not cover piston ring failure, which would pretty much give them a get out of jail free card i would have thought.
Not that I knew when I wrote that, but I am pleased to say their Gold Cover does...
"...pistons & rings, cylinder bores/liners....."
KEV,
All cars have their issues. Rovers K-series - head gaskets, Honda S2000 clutches, Peugeots Idle Valves and speed sensors etc etc.
The fact remains engine failure in MR2's is still very rare.
Compared to many these are solid reliable cars. My car is four years old and has had no mechanical issues to date and uses less than 500mls of oil in 10k.
Don't let it put you off.
s:D :D s:D
Hi simon.
QuoteKEV,
All cars have their issues. Rovers K-series - head gaskets, Honda S2000 clutches, Peugeots Idle Valves and speed sensors etc etc.
Sure... being a pug 306 owner for the last 4 years i know all about idle controller valves... the difference being they cost £50 and tend to last 4 years at least s;) ;) s;) Rover K series... never! hahaha s;) ;) s;)
Problem is, if i was to fork out for an mr2.. i definatly wouldnt be able to afford a new engine haha!
Sorry to drag up an old thread, I'm burning a bit of oil, Diopstick from full to empty in aprox 1200 miles. They car is a 2000 year model with aprox 65000 miles on the clock. I removed the precats aprox 3 years ago, they looked ok at the time. At that stage there was no oil issues.
I've been using Castrol Edge Syntetic 0W-40 for the last 12-18 months, and religously changing the oil every 5000 miles. I know its possible that the oil I'm using is just to viscous and light and maybe thats causing the issue. This weekend I'll change back to reccomended spec and watch consumption.
But in case its not how can I check if the oil control rings are poor? would a compression check show this?
yep do a compression test
if low add a few drops of oil via teh spark plu holes and retry
if the compression improves it's your rings
just thought i'd let you all know, i had symptoms of the pre-cat issue this week (loss of power through the revs, noisy engine etc) and i knew straight away what it was thanks to your posts so thanks!
took it to the local toyota dealership (still under warranty from where i bought it) and they confirmed it was the pre-cat and it was covered under warranty - lucky since it costs nearly £1000!
this all happened shortly after my 02 sensor was replaced which i also heard about on the forum.
i will definitely be getting the pre-cat removed when the warranty runs out - thanks for all the tips guys!
How easy is it to check the precats? and how do I do it?
You need an 02 sensor socket, remove the two 02 sensors at the top of the manifold and shine a torch in the holes. Do a search, there are pics of how the precats should look, basically an unbroken honeycomb structure.
If you can see any damage you are probably fubared.
This only allows you to check the tops though, they could be fine but the bottoms could be breaking up.
Get them gutted or replace the manifold with a Che, asap.
thanks... i'm getteing paranoid now too! My car is a 2003 with 37K miles
me again, been looking at the Che, latest advert on ebay has it at $280 plus $70ish shipping. Has anyone bought one of these recently? btw, Che claims a power increase of 4-6hp. Any idea how much the other precatless types cost?
ignorance was bliss!! s:( :( s:(
Al
Hi Guys,
Well news isn't good, about 3 wks ago I left car in for service and asked them to check the compression. According to them the compression check was ok (I remain dubious) but the asked me to come back when I'd done a 1000 miles. Well called down today and they checked the oil.
The engines using Aprox 1.3l every 1000 miles
They've recommended new piston rings and new valves and seals and quoted me about €1350 Aprox (about £1050 stg).
Will this be sufficient or will I need a new block?
I'd love the idea of a 2zz conversion with Rogue but considering the hassle of going between Ireland and Kenilworth it just doesn't suit me
What do you think?
I've no precats, instead having a PPE manifold and cat. The cat's probably toast but will the manifold be ok? Is it worth doing a flow test on the cat anyhow
for that money may be cheaper going with a 2nd hand engine
if your not happy with teh comp test I can bring my tester to Scotland if your still coming, will only take 10 mins
That'd be great Mark, Thanks
Wouldn't a used engine be likely to fail at some stage though
Re Reading the Rogue 2zz Thread at the moment.
will do, used engine if low miles should be fine and usually comewith a 3 month warranty anyway
Well rang my garage again and asked about using a new or reconditioned engine but their not advising it. They maintain that its better to just change the piston rings, valves and valve seals. A new engine is masively exspensive and there not convinced by reconditioned engines, besides which mines only done 50k.
So should i get them to do it? Or should I look for specilist help like a engine shop. How difficult is the work to do?
Anyone have or heard of this header type I found on ebay? Are they any good? seem less expensive than the che
m http://cgi.ebay.com/00-04-MR2-SPYDER-ZZ ... dZViewItem (http://cgi.ebay.com/00-04-MR2-SPYDER-ZZW30-1ZZFED-BLACK-CERAMIC-HEADER_W0QQitemZ270228192422QQihZ017QQcategoryZ33631QQtcZphotoQQcmdZViewItem) m
comes out of teh same factory but painted so you can't see teh problems
get tehche at least he stands by teh quality
What about this one?
m http://cgi.ebay.com/ebaymotors/00-04-To ... enameZWDVW (http://cgi.ebay.com/ebaymotors/00-04-Toyota-MR2-Spyder-ZZW30-Stainless-Race-Header-MRS_W0QQcmdZViewItemQQcategoryZ33631QQihZ018QQitemZ280217659611QQrdZ1QQsspagenameZWDVW) m
Quote from: "kanujunkie"your right about the O2 sensors on UK and Jap spec cars, however your not removeing the main cat, just the pre-cats, so no it wont bring the CEL light on
Hi! I've finally found a mechanic willing to do the deed on the precats for me (I'm totally useless with my hands). I showed him GSB's excellent how-to posting. Although I quoted the above quote to him he insists I ask the experts about the O2 sensors after getting rid of the precats. Esp on the issue of whether the sensors would send "wrong" signals and interfere with the engine management, or cause the engine management light to go on. So please assure him/me that all he needs to do after getting rid of the precats is put the sensors back as before and that's it, job done.
Any replies would help greatly with my ulcers!!!
Thanks guys.
yep thats all he needs to do
Quote from: "markiii"yep thats all he needs to do
..and I'll confirm if he wants multiple re-assurances. s:wink: :wink: s:wink:
Thank you very much for quick replies. He'll operate on the precats Monday. Will issue post operative bulletin Tuesday.
I was also advised to reset the ECU (by leaving battery off for 30 mins).
The Pre Cats are out drove home and have had no problem! Great result and weight off my daughter's shoulders. Now she can drive without the Pre Cats in the back of her mind. For anybody in the Maidstone area (or further afield) PM me and I'll give you the details of the gentleman who did it all for £50 incl the gasket.
To everybody who kindly offered advice thanks a lot.
Quote from: "demsdad"The Pre Cats are out drove home and have had no problem! Great result and weight off my daughter's shoulders. Now she can drive without the Pre Cats in the back of her mind. For anybody in the Maidstone area (or further afield) PM me and I'll give you the details of the gentleman who did it all for £50 incl the gasket.
To everybody who kindly offered advice thanks a lot.
Suggest you copy this (or similar) in to the Companies who do pre-cats in the sticky at the top of this forum
Have posted details in the Companies who do pre cats.....
thanks for tip.
Please don't use WD40 on or near the O2 sensors.
WD40 is petroleum-based and petrol kills O2 sensors - regularly running (very) rich actually reduces their life.
- I'm currently working up to pre-cat removal; but the garage (temperature) is not being very welcoming at the moment...
Hey folks! First poster here - I'll do an intro later!
I've been looking to get an MR2 Roadster now for a while and will be doing so when I get home (currently working abroad til April). This pre-cat thing is pretty worrying though! I've been googleing like hell to find the Che manifold you've all recommended and have only found this here (http://www.delubozparts.com/ProductCart/pc/viewPrd.asp?idcategory=169&idproduct=1915) Is this the one? It seems odd that the only thing to get is from the US...does anyone in UK do a similar line for similar price? I'm thinking Powerflow etc...
Is Delubozparts the place I need to be heading for..? £207 by my conversion...ouch but cheaper than the TRD one I found somewhere else at, like, £800! If it's the guy I need to get hold of to get one, how is he? Delivery time? Reliability etc..?
Also, fitting of aftermarket manifolds/headers. How much? Time? Can any garage do it? I'm notoriously un-technical when it comes to fixing stuff so it'll def be a garage job!
Cheers in advance for the help!
I had a pre-cat failure about two weeks ago, a couple of days after the repair I started to notice a notice from the engine when accelerating. I have been checking the oil level to see if it's burning up witch is normal, and pressure tested the engine, all fine. Checked all exhaust brackets etc, again all fine.
Can anyone help?
The noise could be unreleated to the pre-cats so check the obvious things like loose heat shields etc first.
If the noise is related to the dead pre-cat failure, it could be the big ends perhaps s:( :( s:( What were the compression results? The material gets into the engine and does all sorts of mischief, particularly the big ends. I'm not sure if a compression test is a good indication of whether any cat material has made it into the engine. Did you change the main cat after the failure?
Jason
Quote from: "Cadde"I had a pre-cat failure about two weeks ago, a couple of days after the repair I started to notice a notice from the engine when accelerating. I have been checking the oil level to see if it's burning up witch is normal, and pressure tested the engine, all fine. Checked all exhaust brackets etc, again all fine.
Can anyone help?
What all was repaired? Did you get a new manifold and downpipe? If you didn't get a new manifold/downpipe this engine is probably toast.
I managed to remove the precats from our MR2 yesterday. I was surprised at just how easy it was. No siezed nuts/bolts at all! I did apply a generous amount of penetrating oil the night before though, which I think helped. Whilst I was under there and had the manifold out, waiting for it to dry after pressure washing, I did an oil change, much easier whilst you have the room under there!
Some tips I would add though:
It's really easy to cross thread the lambda sensors, be extra careful to make sure you are putting in in straight!
The manifold to block clamps are much easier to get in if you leave the manifold studs very loose, this allows you to line the manifold up on the clamps first.
You will need those new compression seals that go between the manifold and the downpipe, mine fell apart when I split the two parts.
Add some copper grease to the plastic undertray screws to make it easier to undo them next time
Now what do I do with the catalytic converter honeycomb? Can I take it somewhere to be recycled?
Oh yes, and one of my precats was beginning to go, there was a region around the tip of the lambda sensor that was mis-shaped. Interestingly, a CEL code P0175 caused me to check it, glad I did!
Chris
Do the pre-cats HAVE to be removed??
The 2002 MR2 I'm soon buying still has its pre-cats intact.
Help much appreciated. =]
Quote from: "thien_le"Do the pre-cats HAVE to be removed??
The 2002 MR2 I'm soon buying still has its pre-cats intact.
Help much appreciated. =]
They don't have to, obviously that is your decision - but I think if you read this thread as a whole you should come out with the conclusion that it would be prudent to do so.
Quote from: "Liz"Quote from: "thien_le"Do the pre-cats HAVE to be removed??
The 2002 MR2 I'm soon buying still has its pre-cats intact.
Help much appreciated. =]
They don't have to, obviously that is your decision - but I think if you read this thread as a whole you should come out with the conclusion that it would be prudent to do so.
Do all cars have pre-cats? If so, wouldn't they have the same problems then?
Or do they just have the main catalytic converter?
sorry my knowledge in cars is extremely poor.
Not all cars have pre-cats, but all Mk3 MR2s do (unless they have been removed).
Most cars do only have a main cat (at least in the UK), hence you not hearing of pre-cat problems very often.
Chris
As a new member, I've been reading the essential stuff. In particular, I'm most grateful to the contributors to this most important topic.
I've recently bought a Jap import, built in 2001, presumably for the Japanese domestic market. Is the pre-cat system fitted to ALL MR2 Mk3 models?
Quote from: "Puerco"Is the pre-cat system fitted to ALL MR2 Mk3 models?
Yes.
Hi I purchased a 2000 mr2 last week from a used dealer - since purchasing i noticed a strange noise, took it to a garage they said it was one of the pulleys on the belt. That has now been replaced, but im continuing to have problems which are getting worse by the day. Ive discovered its used all the oil that was put in on the day of purchase, there are still occasional strange noises from the engine area (different from the pulley noise) and now when i change gear i can feel it pulling back, kind of losing power. After reading up on this forum this all seems to suggest a pre-cat problem, do you think this is the case? I am taking it back to the garage tommorow and they have not suggested this before, so I want to be sure I know what im talking about before telling a trained mechanic that i think this is the case! I am no expert on cars whatsoever. Any help would be appreciated. Thanks
Tell them about the high oil consumption, tell them the engine is knackered and you want your money back and walk away!
Also get them to remove the two o2 sensors from the manifold and visually inspect the pre-cats, see if they are both still there.
Jason
thanks for reply jason -the dealer is paying for the repairs though - do u still suggest getting my money back?. My way of thinking is if they fix it problem solved. Im in love with my mr2 now so would only go and buy another - which again may have the same problem.
Sarah, the engine is fubar, it is almost definetly pre cat failure. Even if they are willing to put in another engine and replace the main cat, i would still demand a refund.
The car was not fit for purpose.
Plenty more out there, DO NOT keep this car under any circumstances.
Quote from: "nelix"DO NOT keep this car under any circumstances.
+1, most definitely !
oh im dissapointed now I dont want to give it up now I have it! But I know what you're saying it makes sense. Thanks
Quote from: "sarahlr3"oh Im dissapointed now I dont want to give it up now I have it! But I know what you're saying it makes sense. Thanks
Give it up, it's a pile of dog faeces, always some for sale on here, you know then you are buying an enthusiasts car.
There are plenty out there, there are even some on here in the private sales section (some of which we actually already know the history of even)
Where are you based and how much ish do you have to spend ?
Im in swansea, wales and if i manage to get a refund then id have about 4000 to spend. My only problem is I exchanged my car with the dealer - didnt pay a penny out infact they gave me 300 pound back becuase my car was worth more. Ive rung them 2 days ago, had alot of attitude and they said I could have my car back but would have to pay for repairs they did to it, even though im not aware there was anything wrong with it.
Tell them the car they sold you was unfit for purpose, they either give you your car back or the purchase price of the mr2 you bought. Drop trading standards into the conversation.
Yes, you don't have to pay for any work they've done on your car. Hopefully they're not spiteful enough to do anything to your old car before returning it. The problem with having them repair the '2 is that they'll probably take short cuts. It needs to be repaired properly otherwise it's going to go wrong again 6 or 12 months down the line and you'll then be paying for the replacement engine.
what would be likely to go wrong 6months down the line? the pre-cats would be removed, i probably already need a new engine now.
Quote from: "sarahlr3"what would be likely to go wrong 6months down the line? the pre-cats would be removed, i probably already need a new engine now.
The main cat will be blocked with oil and precat debris, unless this is also replaced it will simply ruin the new engine.
Sarah, you are here for advice, please believe me, the advice is not to accept the car.
oh yeah i know and thanks for all the great advice - i was just tryin to get a good picture so i can tell them exactly what the score is, wasnt bein funny in my response. thanks again
Quote from: "nelix"Quote from: "sarahlr3"oh Im dissapointed now I dont want to give it up now I have it! But I know what you're saying it makes sense. Thanks
Give it up, it's a pile of dog faeces, always some for sale on here, you know then you are buying an enthusiasts car.
^^What he said. That's the best advice anyone could give you.
ok then time to get lookin for a new one haha better luck this time i hope!
Its not just the precats and main cat unfortunately. The bores will probably be oval due to the earlier design of piston and ring issue on some cars, and that is probably what sets off a lot of the precat failures, and is certainly what causes massive oil consumption. Often the crank would need checking out as well.
So botton line is, reject that car if at all possible.
A lot of the cars for sale on here ( not all) have been owned by enthusiasts, as has been said, and you can also trawl through the posts from that owner and get a flavour of that car's history.
ok just to update went to the garage today they checked the precats when i asked - and I was indeed victim to this fate!! engine was also ruined, so have therefore managed to get my old car back thank god! Im now on the look out for a new one but there aint so many in the south wales area for 4k and am also worried about this happening again. I loved that car though so I think im gonna have to get another. Thanks for all the advice and if anyone sees any that they know of id be grateful. cheers.
Well, not a total loss, but a worth while learning experience!
Glad you've got things sorted for now and good luck with the search s:D :D s:D
no on the whole a very lucky escape! and bang on the mark, im not such a novice now when it comes to the inside of an mr2 haha
WOW!
A success story, really pleased you got it all sorted.
Welcome to the club, lets find you a nice example
Thanks uktotty! yes please do, I need my faith in mr2s restored!
Stick with the TottyMan, I will look after ya s;) ;) s;)
i think sean put it best recently when he said....
Buy on condition
He was refering to TVR's but i am going to apply this logic to every and any car purchase ever!
Philster
Removed my Pre Cats today......... great thread, though it kinda makes it sound alot more simple than it was lol. Unbolt this, unbolt that, done.......... My experience was more, round off this head, round off that one, take a drill and a hacksaw to it, cut your hands and bang your head a few times, get a load of crap in your eyes, swear, swear, swear, swear, swear, swear, swear *5 hours pass* swear swear swear swear....... remove manifold.......... but then take sweet revenge on them dam cats!!!! MAAAAA HAHAHAHAHAAHAHA!!!!! Good times!
Quote from: "Carribdis"Removed my Pre Cats today......... great thread, though it kinda makes it sound alot more simple than it was lol. Unbolt this, unbolt that, done.......... My experience was more, round off this head, round off that one, take a drill and a hacksaw to it, cut your hands and bang your head a few times, get a load of crap in your eyes, swear, swear, swear, swear, swear, swear, swear *5 hours pass* swear swear swear swear....... remove manifold.......... but then take sweet revenge on them dam cats!!!! MAAAAA HAHAHAHAHAAHAHA!!!!! Good times!
but if the 'how to' was like that, no one would be brave enough to take them out. its a simple enough job if your nuts are well lubed, and given a good hammering (missus)
Hi guys, done my research on the precats and know i need to get them out as i have a 2000 mrs and its just ticked over 86000km which im guessing tghe ticking time bomb is ticking louder. s:scared: :scared: s:scared:
my question is, insetad of knocking the precats out is there anything i can replace them with. (this may have been covered but i must of over read it). maybe they can be replaced with a de-cat?
but what is the specification for a pre-cat to de-cat. a pipe? s:lol: :lol: s:lol:
cheers
You can't replace your pre-cats, only buy a new manifold. Buy a MrT one with new pre-cats, or aftermarket without. Plenty available - search will bring up quite a few with pros & cons.
can you buy a decat pipe? iv seen them for sale or are they for replacing the normal cataytic convertor?
Quote from: "roger"You can't replace your pre-cats, only buy a new manifold. Buy a MrT one with new pre-cats, or aftermarket without. Plenty available - search will bring up quite a few with pros & cons.
Hi
I bought an Import model this Feb, love it to bits (I previously drove an MX5 for 5 years, must say the MR2 is much more fun and considerably lighter on the juice).
However I've noticed a touch of blue smoke from the exhaust (maybe 3 times in the last 6 months) seems to be when I set off again after I have been going a little faster than I should. Also noticed that she drinks quite allot more oil than the MX5, I do about 300 miles a week and I am putting in about 1L oil a month (MX5 was about 1L every 6 months), tho some of the forums I read said this was normal so I wasn't too concerned, but after reading a few posts on the precats I'm a bit concerned, The car has done about 55k and was serviced regularly.
I'm going to remove the sensor tonight and have a look to see if the precat is still intact (the MR2 has an aftermarket stainless manifold and very loud twin exhaust, which I was going to get changed as it wakes the neighbours but a mechanic friend says its worth about 700 so I'm not now).
Obviously with the blue smoke there is oil being burnt somewhere, if the precats are ok / have been removed before / weren't in there in the first place, Then I assume its the oval bore problem. So my question is, having read on another forum that the piston rings cant be replaced on an MR2, can someone tell me if that was rubbish. Hopefully if the precats are not the issue then I can just have a re-bore and new rings?
Im also planning to do a compression test this weekend if my mate can borrow the kit from work.
Any advice is greatly appreciated.
Cheers
Quote from: "donnyladjr"I'm going to remove the sensor tonight and have a look to see if the precat is still intact (the MR2 has an aftermarket stainless manifold and very loud twin exhaust, which I was going to get changed as it wakes the neighbours but a mechanic friend says its worth about 700 so I'm not now).
Hi, and welcome.
Pre-cats only live in the factory manifold, so if yours has an aftermarket one, you'll not have them - just before you look in the sensor hole and get scared that they have gone!
High oil consumption can be experienced and is not always oval boring - but you are doing the right thing getting a compression test done. I seem to recall that in some cases others have slowed down their oil consumption by using a different viscosity oil - I'll leave it to others to advise on this.
Cheers,
Stu
Quote from: "donnyladjr"Hi
I bought an Import model this Feb, love it to bits (I previously drove an MX5 for 5 years, must say the MR2 is much more fun and considerably lighter on the juice).
However I've noticed a touch of blue smoke from the exhaust (maybe 3 times in the last 6 months) seems to be when I set off again after I have been going a little faster than I should. Also noticed that she drinks quite allot more oil than the MX5, I do about 300 miles a week and I am putting in about 1L oil a month (MX5 was about 1L every 6 months), though some of the forums I read said this was normal so I wasn't too concerned, but after reading a few posts on the precats I'm a bit concerned, The car has done about 55k and was serviced regularly.
I'm going to remove the sensor tonight and have a look to see if the precat is still intact (the MR2 has an aftermarket stainless manifold and very loud twin exhaust, which I was going to get changed as it wakes the neighbours but a mechanic friend says its worth about 700 so I'm not now).
Obviously with the blue smoke there is oil being burnt somewhere, if the precats are ok / have been removed before / weren't in there in the first place, Then I assume its the oval bore problem. So my question is, having read on another forum that the piston rings cant be replaced on an MR2, can someone tell me if that was rubbish. Hopefully if the precats are not the issue then I can just have a re-bore and new rings?
Im also planning to do a compression test this weekend if my mate can borrow the kit from work.
Any advice is greatly appreciated.
Cheers
If your manifold is something like
THIS (http://i6.photobucket.com/albums/y234/SLAPA/LA%20SLAPA/Che/Che010.jpg) then you don't have any precats, so it looks like you could have oval bores, re-ringing won't cure this problem unfortunately so it looks like re-bore/sleeve (depending on wear) & pistons s:( :( s:(
Be interesting to know how long (if it is a Che header) the manifold has been fitted?
Les
Thanks for the advice, just had a look and its a Che manifold, its been on the car as long as I have had it but that's only 6 months, why do you ask, are there problems with the exhaust manifold also?
I noticed some white markings on the engine block, the kind they use in scrap yards, so perhaps the engine has been replaced, I will check the log book tonight.
If the engine does need reboring how thick are the walls, is it possible to rebore or will it need reshelling? And can anyone recommend any good garages in Doncaster or Manchester?
I've been using 20 - 50 oil as I had some left over from my old car, what's the recommended oil for the MR2 please?
Many thanks
hey guys, i'm relatively a new member too and about to buy an import. i took my mechanic friend to view the car, he checked it over and said it was fine... although he did mention he saw a little blue smoke and smokey smell (car was in showroom also) the car has an aftermarket exhaust, i dont think this has anything to do with it, but i hope that my pre-cats will stay in tact! what do you guys think?
Quote from: "intheend"hey guys, i'm relatively a new member too and about to buy an import. i took my mechanic friend to view the car, he checked it over and said it was fine... although he did mention he saw a little blue smoke and smokey smell (car was in showroom also) the car has an aftermarket exhaust, i dont think this has anything to do with it, but i hope that my pre-cats will stay in tact! what do you guys think?
Blue smoke, smokey smell...........................Wouldn't touch it myself
Well I wa standing there as well... I noticed a little colouring but not alot at all. I'm just wondering if anyone has had this problem and what kind of things it could lead to? First things first! Full service!
I'm wondering if this is a lead to the pre cat problem? I read above about it could be burning oil somewhere? Also checked the dip stick and the oil was kind of low.... Not urgently low but quite low compared to my current car.
Any help would be useful thanks!
Quote from: "intheend"Well I wa standing there as well... I noticed a little colouring but not alot at all. I'm just wondering if anyone has had this problem and what kind of things it could lead to? First things first! Full service!
I'm wondering if this is a lead to the pre cat problem? I read above about it could be burning oil somewhere? Also checked the dip stick and the oil was kind of low.... Not urgently low but quite low compared to my current car.
Any help would be useful thanks!
It sounds like you have already bought it but the other symptoms with low oil are not good signs, all I can say is I hope it goes well for you
Quote from: "intheend"hey guys, i'm relatively a new member too and about to buy an import. i took my mechanic friend to view the car, he checked it over and said it was fine... although he did mention he saw a little blue smoke and smokey smell (car was in showroom also) the car has an aftermarket exhaust, i dont think this has anything to do with it, but i hope that my pre-cats will stay in tact! what do you guys think?
Reject both, the car and your mate the mechanic.
Does anyone know what the compression should be, just checked mine and they came out 150-160 across all 4.
Cheers
I've seen in the range of 175 to 215 on healthy engines. Sometimes can be a bit difficult to tell because oil in the chamber can actually increase the compression reading! .... and gauges can vary too of course. Testing cold will make the reading a little lower - by just how much I have no idea.
As you're consistent across all four and consuming oil that would suggest oval bore. Where we've tested on precat failure it seems to be the cylinders with the shorter run between outlet and precat chamber that suffer most.
Mine was 12.5 bar/181 psi from cold across the cylinders.
Hi folks.......newbie here.
Very interesting read this thread (along with the soft-top drain hole and aerial repair ones).....I've just bought a 05 Mk3 for the missus and this job is going to be tackled one day next week.....my pal has a garage, so soon as he has a ramp free I will be taking a day off graft and cracking on with it.
Thanks to everyone who contributed to this thread....it's a real potential lifesaver if you heed the advice. s:wink: :wink: s:wink:
Hi all
Been following the club for ages now, great information. Sadly though i now need some desperate help.
My car is a 2001 mr2r with 60k miles and yes it still has the precats in.
Its using 1 liter of 5 30w fully synthetic oil ever 500 miles now. It sometimes smokes a bit under heavy load at around 5k revs but not very often. The smoke isn't really oily anyway more black un burnt fuel type of stuff, like its being cleaned out every now and then.
So having studied the threads here on this I'm guessing because of the oil consumption the precats have gone.
The car is quite unique and i really don't want to loose it so My question is. If I de precat it now and get rid of the main cat, put some thicker oil in will that stem the problem and stop the wear? (im thinking yes because there's no more cat rubbish around and the main cat has gone so it wont get clogged with oil and cause pressure problems on the bores.
I'm happy to put a liter of oil in every month because I don't do that many miles if it means i can keep the car.
What do you all think? any advice is very much appreciated as no garage i know seems to have a clue about these cars.
Quote from: "jack2471"Hi all
Been following the club for ages now, great information. Sadly though i now need some desperate help.
My car is a 2001 mr2r with 60k miles and yes it still has the precats in.
Its using 1 liter of 5 30w fully synthetic oil ever 500 miles now. It sometimes smokes a bit under heavy load at around 5k revs but not very often. The smoke isn't really oily anyway more black un burnt fuel type of stuff, like its being cleaned out every now and then.
So having studied the threads here on this I'm guessing because of the oil consumption the precats have gone.
The car is quite unique and i really don't want to loose it so My question is. If I de precat it now and get rid of the main cat, put some thicker oil in will that stem the problem and stop the wear? (Im thinking yes because there's no more cat rubbish around and the main cat has gone so it wont get clogged with oil and cause pressure problems on the bores.
I'm happy to put a liter of oil in every month because I don't do that many miles if it means i can keep the car.
What do you all think? any advice is very much appreciated as no garage i know seems to have a clue about these cars.
Sorry Jack but I don't think there is anything you can do to make things better your problem is
THIS (http://www.mr2roc.org/phpBB3/viewtopic.php?f=11&t=23160&p=288998&hilit=oval+bores#p288479), humungus amounts of oil burning red hot will finish off the cats as well s:( :( s:(
I tend to agree with Les
that said I firmly beleive any 5w oil is way to thin for our engines
decat it, then try a good 10w oil and see how you go, you might get lucky
In that link Muffdan said this
"If you gut the pre-cats you can run with the oval bore problem for a long time (at least 30k with a turbo for me), you just have to top your oil more regularly".
So maybe a little hope? especialy as theres no nocking or tapping as yet?
if it still uses oil I wouldn;t consider it along termer, howver if a thicker oil stops it pissing oil then go for it
yes, you can run with oval bores, but you're using a lot of oil. The level needs to be checked and topped up very regularly and the cost/hassle will add up!
You'll kill your main cat quite quickly too and fail an MOT. Unless you know a friendly MOT station you're going to have to replace the engine sooner rather than later.
*edit: When you get to the visible smoke out the back stage, it's definitely time to get it sorted btw s:) :) s:)
[MOD] Post deleted due to duplication. The question asked has its own thread and replies[MOD]
This is a worrying thread s:scared: :scared: s:scared: I am picking up my little roadster from a garage on Wednesday. I am worried now and thinking all sorts such as, what if these have already started to go and I am being sold a duff motor? How would you know?
Does anyone have any idea what percentage of cars are affected by this problem? I'm seriously considering buying an MR2, probably a 2003 or 2004, but can't afford to buy a car with the Sword of Damocles hanging over it (and me!).
Also, am I correct in thinking Toyota have extended the warranty to 7 years to cover this problem?
Thanks in advance.
I don't think anyone knows a percentage as all we have is anecdotal evidence. All I can say is that as far as I'm aware Toyota took action to change the engine in the facelift model to tackle this problem. The post-facelift failures seem pretty rare from what I've read on this and other forums. I've got my pre-cats but I do check my oil weekly.
Toyota seem to have "unofficially" extended the warranty, if you've got a Toyota FSH.
Quote from: "wayno265"Does anyone have any idea what percentage of cars are affected by this problem? I'm seriously considering buying an MR2, probably a 2003 or 2004, but can't afford to buy a car with the Sword of Damocles hanging over it (and me!).
Also, am I correct in thinking Toyota have extended the warranty to 7 years to cover this problem?
Thanks in advance.
even if you buy a newer car gut them
As above. Also, checking the oil weekly will make no difference at all as by the time you notice any loss it'll be too late, the damage will be done.
While I can see no reason not to gut them if you're in the UK, I would have thought once the problem starts you're engine is on borrowed time anyway. I thought I read about someone having the problem the other day who then ended up with a sub-prime engine anyway. Perhaps I am mis-remembering.........
Thanks for the replies. I'm going to looks at a 2004 model on Friday - wish me luck.
Hi guys,
just been having a read through the pre-cat info, and got a couple of questions....
Are Jap models as equally affected when it comes to precats? - I have a 2002 MR-S recently purchased, so will be looking to sort this out asap - even though there are no symptoms.
I understand that the material can be removed, but is there an aftermarket part that would replace this?
...and... does removal affect the cars emmissions, e.g. MOT problems?
Thanks in advance
S
Yes
No
No
In that order
Quote from: "uktotty"Yes
No
No
In that order
Cheers
There are after market manifolds which will replace the oem manifold, but if you are asking if its possible to replace the pre cats with other pre cats the answer is no.
Hi, Sorry if this ends up in the wrong place but I'm new to these 'puter things!
I have had an MRs jap import for a few years. It's a toy for me so I only do maybe a thousand miles a year in it. It's done 55k and has always been a little thirsty on the oil front. Going up the A34 on thursday all was fine, cruising bout 75ish when I noticed a slight lack of power then a huge amount of blue smoke from the exhaust. Luckily there was a layby not far and limped it in. I am fully aware of the precat thing and suspected this could be it but... the AA recoverd it home and on close inspection the coolant level has risen about 2 inches in the expansion tank, low oil but still just on the dipstick. No horrible noises at all and on testing the compression I got an even 13 bar from all cyls. The plugs are very black and oily but when you start the car there is no pressure from the dipstick tube, which is telling me that the sump isn't under pressure (which it surely would be if the main cat had collapsed). I can't believe that the oil rings on the pistons have all failed together instantly??!! I am now miffed and don't want to lash out on a new engine until I am sure it is terminal. Basically, the engine sounds and runs fine exept for the smoke sreen of blue smoke coming from the exhaust. Any thoughts? Cheers tootall
Blue smoke + oiled plugs = oil getting into the combustion chambers. Only two ways for this to happen (assuming non turbo) , either past the piston rings or down the valve guides; The history of the 1ZZ suggests the former. According to a US MRs chart the compression pressure should be 184 psi (+/- 15) which would seem to be about right in bar however, the presence of oil in the combustion chamber will tend to form a seal on the rings and can distort the compression reading. (The test to distinguish between worn valve guides and worn rings is to do a standard compression test and then pour some oil into the combustion chamber via the plug hole and test again. If there is no change then it is probably guides, if the compression increases then it is probably rings / bore). I would test the compression again with the engine unused for a while and really cold.
Another possibility is a blown head gasket but you would normally only get an issue with one cylinder.
Quote from: "nelix"There are after market manifolds which will replace the oem manifold, but if you are asking if its possible to replace the pre cats with other pre cats the answer is no.
Not quite true,there are some U.S. made units but then if you don't live in California why would you.
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/BsQk2kKGrHqIOKjYEvlLU3VbCBL6FTuS-1.jpg)
Cheers for that. I have just had the exhaust system off and to my amazement the precats are still in place and undamaged!! The main cat seems to be OK (basically it's not blocked and intact). I have fitted a new catless manifold. Drained the oil and nothing nasty looking at all. Refilled and started her up. Still smoking blue with a bit of white. Engine sounds fine apart from a very slight misfire. Like you say, if the head gasket was suspect it would surely point to one cylinder. Anyway, I am going to pull the head next weekend and see whats going on as I have now run out of ideas. On the bright side, if it turns out to be terminal I may well look at getting a 190 celica engine to drop in . I am sure there is a firm in Andover somewhere that has done a few already. Anyone has more ideas on the smoke I would appreciate any input.
Quote from: "life of bryan"Quote from: "nelix"There are after market manifolds which will replace the oem manifold, but if you are asking if its possible to replace the pre cats with other pre cats the answer is no.
Not quite true,there are some U.S. made units but then if you don't live in California why would you.
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/BsQk2kKGrHqIOKjYEvlLU3VbCBL6FTuS-1.jpg)
To pe pedantic, that is a replacement manifold and pre cats, not replacement pre cats, so my answer was correct, the pre cats cannot be replaced.
The blue smoke is definately oil and the white smoke is steam which really does suggest head gasket but if you are pulling the head anyway then I guess you will find out. Good luck.
Not many posts on head gasket failure here and the recorded miles are pretty low for these sorts of problems.
Cheers mrzwei,
With a lack of horrid noises, precats being intact, very good even compression, no foriegn bodies in the oil , the fact it happened instantly and the coolant level has risen a fair bit as well, it does really point at head gasket. I just can't understand how the oil has got from one pot to the other? Unless it's possible that it has travelled via the exhaust manifold somehow? The head is coming off anyway, hope something will be obvious on removal. Thanks for your thoughts.
Thanks to everyone who gave suggestions. Head removed and no glaringly obvious faults. The valves all look fine, must be coming up through the pistons. Bummer. Have sourced an engine from a wreck, 04 plate with 43k on it. Been through a hedge backwards cat c right off. had to part with 1100 sovs for it but only breaker who would guarantee mileage and age and give 6 months warranty. Being delivered on wednesday. Fun weekend for sure. Have got a decat manifold from the states to go straight on. MOT in a couple of weeks so gonna wait and see how she does on emmisions before I splash out on a new cat. Been hell watching everyman and his dog tootling round with their tops down all weekend and my poor baby all sick and stranded in the drive!! Hopefully more clio bating to be done once new lump installed. Again thanks to everyone for their help and hope to see you on the road shortly. Tootall.
If your pre cats went, replace the main cat or it will kill the new engine.
Quote from: "nelix"If your pre cats went, replace the main cat or it will kill the new engine.
+1 for definite ... no joking here, we've seen it before many times.
Thanks for that.
I won't wait then!! After doing 1100 on a replacement block and head, another couple of hundred on a main cat gotta be worth doing. The amount of oil that must of passed through it, I am sure hasn't done it any good. Hopefully be back on the road in a couple of weeks. Will strip the old block when it's out and see exactly what went wrong. Cheers again.
My second engine went wrong...third engine is on the way s8) 8) s8)
http://www.youtube.com/v/140JpPfIhww
thanks for a good thread guys
i followed these instructions and de catted my pre cats last weekend.....no signs of wear on my 2001, 67000 miler but i just wanted to be on the safe side s:D :D s:D
turned out to be quite an easy task in the end...i even managed to keep all my knuckles intact s:bounce: :bounce: s:bounce:
so a BIG THANK YOU to all who have commented/advised....your help was really useful s:bowdown: :bowdown: s:bowdown:
Just like to say a big thanks to everyone for their help when my engine went bang... I have know fitted a low mileage 2006 engine from a celica!! Had to swop the engine mounts, injectors, inlet manifold and the oil dipstick over but otherwise a straight swop. Now running with a jdm racing manifold (no precats) new underfloor cat and TTE exhaust. Sounds glorious but not offensive. Zipped through it's MOT last week and now I remember why I bought the car in the first place!
It seems that I had worn oil rings (2000 engine) and just hadn't noticed really. The head gasket went and pressurised the bottom end pushing even more oil into the block. The precats were actually still intact so I guess I was a victim of the naff early piston design thing?
Can also recommend Hills salvage of Lancashire. They weren't the cheapest but were the only quality yard I could find who not only guarantee the mileage and age of the donor car but gave a full written guarantee as well.
Anyway, if you see a black MRs with full factory bodykit and TTE pipes with a smiley dude behind the wheel this summer, that will be me!
Thanks again.
HI ALL!
Can anyone tell me of a garage in the huddersfield/west yorkshire area that will remove my pre-cats?
or anyone know of where to buy adetted manifold/downpipe?
I've had my engine swapped successfully, but i need to now go one step further and remove the cats...
Many Thanks
Did you look Here. (http://www.mr2roc.org/phpBB3/viewtopic.php?f=11&t=11137)
Replacement headers can be bought from che on spyderchat, m http://spyderchat.com/forums/showthread ... -48-States (http://spyderchat.com/forums/showthread.php?41591-Che-1zz-Header-Limited-Stock-Sales-Reg.-GB-225.00-Now-195.00-Free-S-H-48-States) m
Just spotted these on Ebay. Anyone any experience of these? Seem cheap enough.....
m http://cgi.ebay.co.uk/Toyota-MR2-Roadst ... 5d29dc1878 (http://cgi.ebay.co.uk/Toyota-MR2-Roadster-1-8-Decat-Exhuast-Manifold-00-07-/400134248568?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5d29dc1878) m
No experience with them, but they are missing the lower bracing which prevents tubular manifolds from cracking.
s:D :D s:D OK good call, I'll disregard it then. Cheers
Hi Guys,
I've just signed up to this club after looking up advice in the forums, thought I may be able to contribute something (maybe!)
Well, I bought an MR-S back in October 2010, a 1999 W reg. Only had 55,000 on the clock and it has been fantastic.
Up until recently I checked the oil say once a month, but a few weeks ago I noticed it was very low, no changes in performance or engine sounds - also no oil warning light lighting up. No exhaust smoke and no oil leaks on the drive way....
I paid a trip to my local Toyota dealer and spoke to a very knowledgeable mechanic there, he explained that the 1ZZ engines can be "real oil burners" and gave me the impression it may be ok. He explained that Toyota had extended the warranty on these engines, providing it had full service history.... and "only lost" 1 litre of oil per 1000 miles...
So I dug out the service books and went back the same day....
Unfortunately, he had found out the extended warranty only applied to cars less than 7 years old (bugger) and if the car had full Toyota service history (bugger).
Having read about Pre-cat failure and the damage caused, I am bricking it....
I have yet to take out the O2 sensors and have a look but am I too late? Where do I go from here?
Any advice no matter how brutal would be greatly appreciated,
Thanks in advance guys.
check precats, remove, change oil and hope
main cat may be toast depending on the state of the precats
...have been following this thread with interest ....bought mine last year Oct....2002 model, 44K km's (in 8 years!?), thought it was a Toyota - you can't go wrong! A Yaris (do you have them in the UK..? smallest of the Toyota range) with the same k's would cost me the same...for my wife (of course!). Started reading...joined the club...heard about the pre-cat thing...was told about oil usage on purchase...didn't care, I just loved what I saw...bought her anyway!
Over the weekend, slowing down to 60km/h (from 140) I noticed she was running on 3 cylinders, CEL came on, I thought it was a faulty plug.
She had been using almost a liter of oil every 550k's - that's a hell of a lot...performance was still good (although I did not have a yardstick to measure from) and I felt that if the engine goes, so be it, I had a policy covering any mechanical failure.
Well, this weekend was that time.
A piece of pre-cat lodged itself in one of the valves and broke a small edge off the valve....allowing the exhaust to breathe freely and cause the cylinder to fail.
She's at a reputable Toyota dealer (voted best in the country a couple of times) and I spoke to the mechanic personally....told him what I read...he handed me the outlet manifold and there it was....cracked pre-cat on both sides....checked the play on the pistons in the block...Paul (the mechanic) said that there was excessive play....hence the oil usage.
I have put in a claim for new valves, new rings and bearings....I hope the claim goes through!
They have to include the new outlet manifold and pre-cat in the quote but have given it ( the manifold) to me and I proceeded to clean it out this afternoon...screwdriver and mallet...no problem.
Started reading intensively about 02 sensors - Paul reckoned that the pre-cat sensors would communicate it's info...the post-cat sensors would do the same and the computer would still spit out the right amount of fuel. Reading all the posts, including the official vote, it seems as if no mod is needed on the sensors...IS THIS CORRECT?...IS PAUL CORRECT?! s:bowdown: :bowdown: s:bowdown:
thanks for your time...
can anyone tell me if I need to replace my main-cat or can I clean it with compressed air....also, what is the story with the 3 O2 sensors....have been reading a lot on the forum but there seems to be differing views....can anyone help?
My '2's engine is in a million pieces as I type this... s:flame: :flame: s:flame:
I would replace the cat, why take the chance on fubaring a new engine?
Yes, the sensors SHOULD be OK, but if they've been spurted with oil, you never quite know. If you can get them replaced under warranty go for it. And as Craig says, replace cat as well.
You have the chances of both messing it up all again or getting yourself a blockage so performance is lost after about 4K revs. Air MIGHT clean it out, but again its a risk.
The car only has 71K km's on her....I feel a good blow with compressed air in the opposite direction must dislodge any particles stuck there. My insurance won't pay çause it's "wear and tear"! I will clean the main cat and leave the sensors as they are. I am also having the rings and big-ends replaced. The cylinder walls look very good with no scoring and the original honing marks still clearly visible. She burnt an exhaust valve....reading up as much as possible about this but all roads seem to lead to pre-cats.
When one of mine fell through, I took the cat out and tried fir a few hours to unblock it, using a needle and compressed air. It freed up the airflow, but didn't cure it. When I took it to an exhaust specialist, they told me that the cat was nackered, so I had a sports cat as a replacement. Was a great deal cheaper than toyotas cat quote.
Just submitted a vote on "post pre-cat gutting - problems with 02 sensors" ...unfortunately had to vote ÿes".
Got the baby back from the Toyota dealer this afternoon. The mechanic said that she was idling fast, about 1500rpm. He suggested that it may be the gutting of the pre-cats that was causing the fast idle.
I noticed when she cooled down that the idle alternated between 700 and 1500rpm...when hot it goes to 1500 and when cold it idles normally...for a while!
To recap: I burnt a valve when a piece of precat lodged itself in the valve seat....when they had the motor in pieces I felt they may as well replace the big and small ends together with the piston rings and valves. She had been using oil since I bought her at 44k km and the valve burnt at 71k km's. I never noticed a difference in performance and oil usage never increased but she was using more than two pints per 1000km's. I had topped up the oil the day before the valve incident.
FYI the cost was about 950 pounds, R11500.00 (Just found out my pc has no "pound" key!...is that possible?!)
Has anyone have any ideas on the idling question?
I have seen a thread where someone suggested taking the main cat sensor wire and connecting it to one of the precat sensors...can anyone shed light on this?
Quote from: "scipio"Just submitted a vote on "post pre-cat gutting - problems with 02 sensors" ...unfortunately had to vote ÿes".
Got the baby back from the Toyota dealer this afternoon. The mechanic said that she was idling fast, about 1500rpm. He suggested that it may be the gutting of the pre-cats that was causing the fast idle.
I noticed when she cooled down that the idle alternated between 700 and 1500rpm...when hot it goes to 1500 and when cold it idles normally...for a while!
To recap: I burnt a valve when a piece of precat lodged itself in the valve seat....when they had the motor in pieces I felt they may as well replace the big and small ends together with the piston rings and valves. She had been using oil since I bought her at 34k km and the valve burnt at 71k km's. I never noticed a difference in performance and oil usage never increased but she was using at least two pints per 1000km's. I had topped up the oil the day before the valve incident.
FYI the cost was about 950 pounds, R11500.00 (Just found out my pc has no "pound" key!...is that possible?!)
Has anyone have any ideas on the idling question?
I have seen a thread where someone suggested taking the main cat sensor wire and connecting it to one of the precat sensors...can anyone shed light on this?
Precat gutting made no difference to my idling, but a couple of jobs first time round..... Clean the MAF and reset the ECU (battery off for 30 mins). The dealer should probably have done both, but you're never sure.
Quote from: "roger"Precat gutting made no difference to my idling, but a couple of jobs first time round..... Clean the MAF and reset the ECU (battery off for 30 mins). The dealer should probably have done both, but you're never sure.
I cleaned the MAF sensor a couple of weeks ago and the car definitely had it's battery out for a couple of days.....but will try both suggestions again....thanks for that Roger.
Started the job todaqy of taking out old precat and fitting with a decat manifold. To make life easier i took off the exhaust and went to it from the back. Exhaust came off fine as i only fitted it 6months ago. The the problems started!!
Three nuts came out fine from the heatshield then the third rounded s:evil: :evil: s:evil: i tried vice grips, then chiselling so i could try a flat head, then filed the sides to get a grip with a spanner, then hammerd on a smaller socket and just basically buctehered it. In the end i just angle grinded the little sfuck fuck sfuck er off. s:twisted: :twisted: s:twisted:
Any how, the precats look in tact s:D :D s:D .
Now, i the bolts holding the cat to the precat are stiffer than michael jackson in a nursery. and the five holding the top of the precats to the engine look like itd be easier to ice skate uphill.
I soaked all the bolts the night before and for a few hours in the morning, and it did diddly squat.
Anyone got any secret method to getting these buggers off?
The only thing i didnt do was raise the temp of the car before starting as i took the exhaust off thinking i was being clever and making life easier
Just a word of warning to anyone who is going to do there precats themselves or repclace manifold. As a follow up to my above post, in total i had to chisel off 5 nuts. they were all rusted on and with the car being a 2000 i could blatenly see these had never been moved since fitment. The three nuts holding the cat to the precat are very stubborn, without a ramp it near impossible to get them off with the car just up on stands, two had to be chisseld off and the other needed some serious weight behind it to start turning. I found that when i took the heat shields off and lifted part of the cat up past the block i could bring the precats towards me and get to the nuts from ontop. Was much easier from then on.
Hi All
Some really interesting reading. I have a 99 Jap import with about 70k miles and naturally worried now.
Can anyone recommend a good replacement manifold and where to get one? Want to change it before its too late.
Thanks
m http://www.ebay.co.uk/itm/ws/eBayISAPI. ... 0410646673 (http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=380410646673) m
Thanks Richard,
Have you got this fitted to your car?
Hi everyone I bought a 99 mr-s a couple months back and to get through mot had a new head gasket done its only done 58k tho. I ran it in for over a thousand miles at 3000 rpm but lately noticed a noise coming from engine louder than normal and when I hit a incline in dies out and stugles to do 50-60 could this be the pre cats as reading all this has got me highly worried and if so does it sound like its to late for me??
Hey guys, I don't know much about cars (fair to say, I am "mechanically retarded"), but am planning on having a cat-free manifold put in very soon. I've done some basic research on this site already, but if someone can take a look at this one
m http://www.ebay.co.uk/itm/TOYOTA-MR2-RO ... 483cb398aa (http://www.ebay.co.uk/itm/TOYOTA-MR2-ROADSTER-1-8-DECAT-EXHAUST-MANIFOLD-00-07-/310256048298?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item483cb398aa) m
and confirm whether or not it would suffice, and comment on the quality of the product if possible, that would be much appreciated!
Matt
Looks exactly like mine. It doesn't appear to have the heat shield lugs but the shields are not essential.
You can always wrap the manifold later if you wish.
It won't have a fixing to help support the manifold buy it will only weigh 4.5 kg compared with the original at 10kg.
I've made a bottom bracket but it was tedious to say the least.
You can use the bottom gasket but make sure you use a Toyota manifold to head gasket. Do not use the one supplied with the manifold.
I'm quite happy with mine, don't believe the blurb about extra power, just be glad to be rid of the precats.
Watch the tyres/wheels and keep reading the forum.
You won't go far wrong.
Welcome by the way!!
QuoteIt won't have a fixing to help support the manifold buy it will only weigh 4.5 kg compared with the original at 10kg.
I've made a bottom bracket but it was tedious to say the least.
Am I correct in assuming that this fixing is an absolute necessity with the new manifold, despite it being lighter? And is that something any mechanic/garage worth their salt will be able to sort out?
I'd say its necessary. Unsupported, it'll still work, but on an aftermarket manifold this isn't so much about supporting the weight. Its more about keeping stress off the pipework by having both flanges firmly attached to the engine block.
Ok, I see. Thanks for the advice.
Does anybody know what size dimensions the bolts/screws (two of them) are on the top of the heat shield covering the pre-cats? The ones on top of mine have suffered heat degradation quite badly (turned into a brittle, plastic-like substance...) and I know that, once removed, they will not go back on, so I don't want to remove them without a replacement!
does the MK3 from 2003 still have the pre-cat problem?
Quote from: "fulmar/88"does the MK3 from 2003 still have the pre-cat problem?
You'll find more detailed information if you have a bit of a search around on here but my understanding is that the facelift included some small changes that help prevent the root cause of the precat failure (oil control ring thingy).
However some facelifts have still suffered from the same issue. It purely lessens the chance slightly.
I believe there was also a small revision again in 2005 (?) or 2006 that once again improved it.
many thanks.
Greetings all...I have a 2001 MR2 with 37k on the clock. 1 previous owner, serviced every 6000 miles...wish to avoid the dreaded pre-cat problem - anyone know of a garage in Surrey in the Epsom area who would remove them for me?
OR
Is it better just to buy a new manifold and get someone to fit it for me?
(I watch a lot of 'wheeler dealers' but my mechanical skills aren't exactly on the same level as Edd China's alas!) Easy job?
Hi and thanks for a good explanation Ekona.
I have recently bought an 2003 MR2 from my friend who had it from new, it had done some 29000 miles. I have recently found this forum and read your article about pre cat failure, and would like to know how the 2003 car is better, ie does it have metal substrates in the pre cats. As I dont want to take out the pre cats for no good reason, but if they are ceramic I will definitly take them out.
I probably ought to say that I am retired from an high performance engine design and development background.
Thanks again for your input.
6100art
They are definitely ceramic. You can check and determine condition if you take out the sensors.
Have fun! Heatshield and the three manifold to exhaust pipe fixings can be little sods.
Thanks Jandaw. I will take them out.
6100art
I recently had my precats removed by Luke at Pacific Works in Luton, a really nice guy and he did a great job
Just put a replacement engine in my 2001 roadster, started it up smokes badly whiteish brown smoke ,first thought was headgasket but on reading some of this could it be pre cats ??? Sounds smooth no rattles , nor does it seem to be pressurising or loosing water .. ??
Anyone know of a garage that will de cat the pre cat in South Wales? Thanks guys
Quote from: "shep1975"Anyone know of a garage that will de cat the pre cat in South Wales? Thanks guys
I took mine to these guys to get them removed for £70, they've done quite a few so are experienced doing it. Swansea based.
m http://www.targetmini.co.uk/import/index.html (http://www.targetmini.co.uk/import/index.html) m
Would you expect the pre-cats to have failed by now on a 2000(X) 80K MR2?
Quote from: "Optimum"Would you expect the pre-cats to have failed by now on a 2000(X) 80K MR2?
It really depends on how well it's been looked after for those 80k miles.
Had precats removed on my 2001 MR2, 70000 miles on the clock. They seemed to be in perfect condition.
Believe it was a pig of a job due to bolts being so rusty.
Anyone know of a garage in Devon/Cornwall that will de cat the pre cat? I'm based in Exeter.
i had my pre cats removed yesterday.. when we reattached the manifold, my mechanic put some gasket maker paste in between to serve as gasket. (the one that comes in tube) .. after reassembly, the gasket paste started to heat up and emit some burning odor.. is it normal? would it not catch fire later?
please reply asap
thanks
I guess that your mechanic used gasket cement because the gasket was not available.
Hopefully it was exhaust gasket cement, if so it should not catch fire. However gasket cement is usually considered to be an emergency/ quick fix and I suggest is not a substitute for the correct gasket type.
Worst case should be the gasket cement will fail over time (how long?) and this will be noticeable audibly, it could then be laborious to scrape the manifold faces clean again to fit a gasket.
Hi,
My car failed at MOT because of High Carbon Monoxide (CO). I changed the O2 sensors before the MOT at a Toyota Dealership.
At idle speed it's Ok, but at 2500rpm/3000rpm the Carbon Monoxide is excessive.
Car has 127.000Km (80.000miles) on the odometer, oil consumption problem seems Ok since it's almost at the "Full mark" after 7.000Km. I used Castrol Edge 5W30
Right now the car has a TRD exhaust manifold, and when I removed the OEM manifold realised the pre-cats where already been removed somewhere in the past.
Toyota says the MOT failure it's probably because the pre-cat's - or the lack of them - but after reading some articles in this and other forums I think it's more likely that Main Cat need to be replaced.
Nevertheless, at Toyota they said to me they can't be sure if the Main Cat it's OK
Since Toyota can't give me 100% sure what it is, as anyone have some opinion about that?
I'm about to go and buy the MainCat since some users also removed the Pre-Cats and their cars passes the MOT test.
Air filter is OEM, and spark plugs are NGK recommended in the owners manual.
Did they make sire the car was warned up before testing?
Yes. The MOT center is about 5km away from the Toyota dealer, and they told me they accelerated the car a bit to see if the values come to the normal.
I've just talked to a friend of mine that had a Celica 7gen with the 1ZZ-FE and he had the same problem with CO. At idle speed ok, at 2500/3000rpm too high. He solved the problem by cleaning the Air flow meeter... I'll try that tomorow.
If that doesn't work I'm not sure what to do. Change de Main Cat or buy a new pre-cat manifold :s
I am sure it is not the removal of the precats that failed the test.
See my- PreCat removal and MOT -thread in the general section.
Note I had replaced spark plugs and cleaned the MAF also after decatting and before the test.
There are a lot of us passing MOTs without precats.
Give it a bit of loving, a good service, clean the maf and replace the plugs then reset the ecu and have a nice drive out.
what about some fuel treatment - like Millers - my local garage says this has helped cars pass.
Is it possible to reload the pictures from the earlier posts? I'd like to see the pics of how the healthy cats should look.
Quote from: "Joesson"I guess that your mechanic used gasket cement because the gasket was not available.
Hopefully it was exhaust gasket cement, if so it should not catch fire. However gasket cement is usually considered to be an emergency/ quick fix and I suggest is not a substitute for the correct gasket type.
Worst case should be the gasket cement will fail over time (how long?) and this will be noticeable audibly, it could then be laborious to scrape the manifold faces clean again to fit a gasket.
thanks bro.. i looked at the tube and it says it is applicable for use in the exhaust
Quote from: "cptspaulding"Is it possible to reload the pictures from the earlier posts? I'd like to see the pics of how the healthy cats should look.
Have a look at the subject .... l viewtopic.php?f=11&t=3507 (http://www.mr2roc.org/phpBB3/viewtopic.php?f=11&t=3507) l
Realised too late when I got home it must be the firewall at my office blocking the pics. I can see them fine at home.
So with huge thanks to Loadswine my pre-cats have now been removed s:D :D s:D
Pre-cats in s:evil: :evil: s:evil: s:twisted: :twisted: s:twisted: s:evil: :evil: s:evil: s:twisted: :twisted: s:twisted:
(http://i41.tinypic.com/1sinvs.jpg)
(http://i43.tinypic.com/907wxv.jpg)
Pre-cats out! s:bounce: :bounce: s:bounce: s:bowdown: :bowdown: s:bowdown: s:bounce: :bounce: s:bounce: s:bowdown: :bowdown: s:bowdown:
(http://i40.tinypic.com/30j7g42.jpg)
Expensive rare materials for the dustbin s:) :) s:)
(http://i44.tinypic.com/2w5rhb6.jpg)
Didnt realise how thick the pre-cats were s:scared: :scared: s:scared:
(http://i39.tinypic.com/2ry4mkz.jpg)
And finally my sprayed manifold that went back on s:) :) s:)
(http://i42.tinypic.com/2dkl1qp.jpg)
Is there any benefit to fitting a new manifold without the pre-cat chambers?
About my CO problem in the MOT, I bought a new main cat and maintained the TRD exhaust manifold. And it passed s:) :) s:)
Sorry it take so long to leave here some feedback.
Hi all,
This is my first post as I hope to pick up a 2003 (ish) MR2 in a couple of weeks (excited!) so want to do the removal. I'm looking at the details on the first page of this tread, but all of the photos that GSB showed (as quoted in post 1 by Ekona) are not working so I can't see the details. Is there another link with them in?
Also, how long would you expect a 'tinkerer' to take to do this job. I've done breaks, suspension, rads, alternators etc. on previous cars but this is probably the biggest job I will undertake.
Thanks,
Mark
Hi there it took me two hours from start to finish, but everything came off with no problems. If you look at the thread , pre cat removal how I did it, page 15 there is a link to spyderweb where you can see pictures on how to do.
Hope this helps.
Quote from: "Lurch"Hi there it took me two hours from start to finish, but everything came off with no problems. If you look at the thread , pre cat removal how I did it, page 15 there is a link to spyderweb where you can see pictures on how to do.
Hope this helps.
That's good to know Lurch, so if I allow half a day then that will be fine. I just didn't want to end up with the car out of action for ages after I just pick it up.
Precats out or just replace the whole manifold?thoughts?
Hello, first post here, which is a very helpful forum. I picked up a 54plate with 47k yesterday. It has a TTE exhaust which was mentioned earlier in the thread as having metal precats instead of ceramics. Please can someone confirm this.
Also is it possible that the TTE system could have been fitted later cat back? In which case is there any way to check whether I have the TTE manifold without removing it to check what the honeycomb is made from.
Thanks
Hugh
TTE exhaust is only a cat back system so you still have your original catalyst and manifold (with precats).
You may have confused this with the TTE turbo which does have metal precats.
Ummmm, I've got a 56 reg mr2. It's on 32k at the mo.
Read somewhere that the pre cat prob had been fixed by 2006 models? Does anyone know if this is the case or should I be getting the pre cats checked??
Is there an easy way to see if a previous owner has removed the pre-cats? i've got a 2000 model with 44k miles, spent it's entire life on an island with a maximum speed limit of 35mph, I've read the ways to check the state of the pre-cats on the first post but is there anything noticeable you can check to see if someone has already removed them?
I am sure the only way to tell if they have been removed is as stated in the first post: Remove the two O2 sensors.
As stated this is best done with a made for purpose socket spanner.
If you do not have one there may be ROC member near to you with one or order one from the www.
Either way while you are waiting for the spanner (if you are not using the car) soak the sensor /manifold joint with PlusGas or similar penetrating fluid.
If your 2 has lived its life at such sub sonic speed you will likely need to check/clean or replace the spark plugs and clean the MAF.
Important, enjoy!
Mine look like this. Big power loss, struggles to rev
(http://i1038.photobucket.com/albums/a469/monkulas/Mobile%20Uploads/20140720_153015.jpg) (http://s1038.photobucket.com/user/monkulas/media/Mobile%20Uploads/20140720_153015.jpg.html)
(http://i1038.photobucket.com/albums/a469/monkulas/Mobile%20Uploads/20140720_152439.jpg) (http://s1038.photobucket.com/user/monkulas/media/Mobile%20Uploads/20140720_152439.jpg.html)
There is not a lot left,hence your power loss. s:-( :-( s:-(
Quote from: "Joesson"I am sure the only way to tell if they have been removed is as stated in the first post: Remove the two O2 sensors.
As stated this is best done with a made for purpose socket spanner.
If you do not have one there may be ROC member near to you with one or order one from the www.
Either way while you are waiting for the spanner (if you are not using the car) soak the sensor /manifold joint with PlusGas or similar penetrating fluid.
If your 2 has lived its life at such sub sonic speed you will likely need to check/clean or replace the spark plugs and clean the MAF.
Important, enjoy!
Thanks s;) ;) s;)
I've recently done a pre-cat removal and have a few thoughts/observations that may be of interest. First I will summarize my recommendations, prioritised:
1) Get an aftermarket manifold (someone sent me a link for a 90 quid one which is good)
2) Wrap the manifold in heat wrap
3) consider exhaust situation with pre-cat removal
Now I shall explain:
I gutted my manifold and cleaned it out. Fairly straight-forward procedure as described on the first post. I had no issues at all with bolts, but as I spent almost 70 quid on new ones and gaskets...figured I might as well replace them. I cleaned out the manifold after gutting it with a variety of products to make sure it was nice and clean.
I also added a TTE Exhaust at the same time...this may or may not contribute to my observations.
I noticed one main thing on a good run out; there is a clear difference in power delivery. Both good and bad.
The very first time I took it out I noticed an increase in low-down torque. This makes sense. The exhaust is more free-flowing without pre-cats and the TTE exhaust which is less restrictive. I was a happy camper.
Then I noticed, it has lost some "oomph" in high load.
Theory behind it (in my opinion): Initial torque is increase as the exhaust system is less restricted and air flow is not at max. There isn't much pressure behind the exhaust, so it flows happily straight through the manifold and out the exhaust. Happy days!
Now in high load there's something new; there's now two nice big empty chambers where the pre-cats used to be. You mash the loud pedal at 50-ish mph and exhaust rushes into the manifold and into the big empty chambers, wanting to continue rushing out. Instead, it finds the narrowed opening from the pre-cats to the main cat. Now there's a queue of exhaust gas building in the chambers as all the little exhaust molecules line up single-file to get into the cat converter in an orderly British queuing fashion. The queue builds up and now there's a blockage. More exhaust comes flying in from the engine and is now hits the back of the queue. Back-pressure! Now opening up the exhaust too much is also not good. We know we need to keep the velocity of exhaust gasses up to keep a good flow. Air flows faster through a straw than it does through a sewage pipe given the same input. But do we really want to have exhaust gas almost making its way back to the exhaust valves? ...I don't.
Engine is now no longer running efficiently and loses some torque/pull.
So yes, removing pre-cats is a good thing. Especially on a 2004-ish or earlier car of course, as said before. Peace of mind etc etc bla bla. But it would be great if someone could measure the impact of this on a dyno and maybe check the exhaust valves pre and post cat removal, after a few thousand miles to prove/disprove my theory.
In the meantime, if I were to redo this, I'd get an aftermarket manifold and wrap it. I took my heatshields off, and ran it like that for a bit and the heat in the engine bay was just ridiculous. Who knew exhaust manifolds got so hot?!?! hahaha...I kid...
I bought 10 quid of exahust heat wrap from "the bay" and spent 30 minutes wrapping it. Had a hard 45 minute run up Hartside pass and afterwards opened up my engine bay and was actually able to touch my manifold (don't ask why I tried). So it makes a huge difference. Much better than heat shields.
My 2-pence...done.
I once had a pop on the standard exhaust... s;) ;) s;) (gutted precats)
Quote from: "James and his MR2"I once had a pop on the standard exhaust... s;) ;) s;) (gutted precats)
I'm popping all over the place now. It's not loud at all. But I can just hear it when I let off
Quote from: "shnazzle"I'm popping all over the place now. It's not loud at all. But I can just hear it when I let off
Don't eat so many beans then. Must confess, love a good exhaust pop/bang/grumble s:) :) s:)
Surely this 'popping' can't be good for the car either? if most cars don't have pre-cats how does the gas travel through it without building up and popping?
Quote from: "Roadster"Surely this 'popping' can't be good for the car either? if most cars don't have pre-cats how does the gas travel through it without building up and popping?
If you read my lengthy post above.... I think removing pre-cats actually reduces performance overall. Unproven. But just what I've noticed
Quote from: "shnazzle"Quote from: "Roadster"Surely this 'popping' can't be good for the car either? if most cars don't have pre-cats how does the gas travel through it without building up and popping?
If you read my lengthy post above.... I think removing pre-cats actually reduces performance overall. Unproven. But just what I've noticed
I read it, I know it's unproven but your not the only person to mention a popping sound when they are removed, is it a minority which get the popping sound do you think?
Quote from: "Roadster"I read it, I know it's unproven but you're not the only person to mention a popping sound when they are removed, is it a minority which get the popping sound do you think?
It's not particularly audible on mine, and that's with the TTE exhaust. You can hear it pop internally a bit.
So most people won't realise it I reckon. Not a problem with free flowing after market manifolds.
Mind, I don't think the popping is a bad thing. It's not banging. Just sounds like healthy, normal popping made more audible by the open pre-cats chambers
I was able to take the right o2 sensor out to take a look at the precats from the top but i'm struggling to take the left one out, I've used loads of PlusGas but even my brother (who is fairly strong) isn't able to get the bolt off the left one, i'm turning it anti-clockwise just like the one on the right but this one won't budge, the one on the right was replaced by a previous owner not too long ago so wasn't too hard.
Is there anything else i can do to remove this o2 sensor without breaking it?
Has the Plus gas been allowed to work for some hours?
Are you using a slotted socket?
If so this could be limiting the torque applied to the sensor as the slot in theory will allow the socket to gape.
As you need to replace it anyway I would cut off the cable and then try with a six sided regular socket with an extension and and a wrecking bar or a piece of heavy gauge tubing to increase the leverage.
Keep the socket pushed well down onto the sensor.
If still no movement heat will be your friend.
Some have had success with running the engine to heat the manifold.
Others have tried applying heat to the manifold area around the sensor with a blowtorch.
Warning, as recently noted, Plus Gas is flammable.
A case for the 3 P's again I think.
With one sensor removed, it should be possible to remove the heatshield. With that out of the way, you should be able to get a 22mm ring spanner on the stubborn sensor. Might be worth trying a bit of heat as well. Threads have been known to strip with really stubborn sensors. There is no predicting that, unfortunately.
Quote from: "Joesson"Has the Plus gas been allowed to work for some hours?
Are you using a slotted socket?
If so this could be limiting the torque applied to the sensor as the slot in theory will allow the socket to gape.
As you need to replace it anyway I would cut off the cable and then try with a six sided regular socket with an extension and and a wrecking bar or a piece of heavy gauge tubing to increase the leverage.
Keep the socket pushed well down onto the sensor.
If still no movement heat will be your friend.
Some have had success with running the engine to heat the manifold.
Others have tried applying heat to the manifold area around the sensor with a blowtorch.
Warning, as recently noted, Plus Gas is flammable.
A case for the 3 P's again I think.
I'm using a 02 sensor socket 22mm on a ratchet, I have to replace the cable? do you mean if i force the sensor out?, ill try an extention without cutting the cable if i can, from what i can tell from the right precat they are starting to go, but if i take them out ill need to get this left sensor out anyways, lol after yesterday i'm quite aware of the flammability of the PlusGas s:lol: :lol: s:lol:
Quote from: "loadswine"With one sensor removed, it should be possible to remove the heatshield. With that out of the way, you should be able to get a 22mm ring spanner on the stubborn sensor. Might be worth trying a bit of heat as well. Threads have been known to strip with really stubborn sensors. There is no predicting that, unfortunately.
The bolts at the top of the heat shield have pretty much disintegrated, which was my next question when i plan to remove these precats in a couple weeks, it's a 2000 model and has done 44k miles and spent it's life in Guernsey (A tiny island 35 miles around the entire coast) with a maximum speed limit of 35MPH ...some of the precat is looks a bit bad
Sorry, I understood the sensor was not working. It certainly wouldn't if you cut the cable.
As loadswine pointed out it is much easier to access the sensor with the heatshield removed. That is if the heatshield wants to come off!
For the dodgy heatshield bolts, Irwins may work, or it will be a matter of drilling the bolt heads off and seeing if you can get the remainder out with stud extractors.
Quote from: "loadswine"For the dodgy heatshield bolts, Irwins may work, or it will be a matter of drilling the bolt heads off and seeing if you can get the remainder out with stud extractors.
You mean these? m http://www.homebase.co.uk/en/homebaseuk ... :1o5|bku:1 (http://www.homebase.co.uk/en/homebaseuk/bolt-grip---5piece-set-609676?_$ja=cgid:13855220056%7Ctsid:49590%7Ccid:320624896%7Clid:66433371226%7Cnw:g%7Ccrid:46736128816%7Crnd:15218375789324621917%7Cdvc:c%7Cadp:1o5%7Cbku:1) m
my right precats m http://postimg.org/gallery/1qbjtoca/41e137a9/ (http://postimg.org/gallery/1qbjtoca/41e137a9/) m
Would you say they are. not bad or getting there or urgent?
Those heatshield bolts are very badly corroded, not sure there is very much for even Irwins to get hold of. I have managed to remove completely rounded bolts with them before, but they did, at least have a head.
If you were going to invest in a set anyway, then go for it, but if they will just be used for this job, then drill them out perhaps, especially if you intend using an aftermarket manifold upon re assembly.
I would say the precats really want to come out , in my opinion. It does look as if they have started to degrade.
If I installed an aftermarket Manifold ( m http://www.ebay.co.uk/itm/TOYOTA-MR2-RO ... 4897.l4275 (http://www.ebay.co.uk/itm/TOYOTA-MR2-ROADSTER-1-8-DECAT-EXHAUST-MANIFOLD-00-07-MF6110-/310256048298?_trksid=p2054897.l4275) m ) like that one, would fitting it need any adjusting to anything or would if fit exactly the same as the stock manifold? for £130 I don't see why it's worth just gutting the rotten stock one? would it affect the o2 sensors? Sorry asking far too many questions o.O
Quote from: "Roadster"If I installed an aftermarket Manifold ( m http://www.ebay.co.uk/itm/TOYOTA-MR2-RO ... 4897.l4275 (http://www.ebay.co.uk/itm/TOYOTA-MR2-ROADSTER-1-8-DECAT-EXHAUST-MANIFOLD-00-07-MF6110-/310256048298?_trksid=p2054897.l4275) m ) like that one, would fitting it need any adjusting to anything or would if fit exactly the same as the stock manifold? for £130 I don't see why it's worth just gutting the rotten stock one? would it affect the o2 sensors? Sorry asking far too many questions o.O
Nothing else to do, just bolt on and enjoy. You may want to wrap it to reduce engine bay temps. However do a search on here for advice on wrapping or not wrapping, as there are many opinions on if you should or not.
Toolkit required
Trolley Jack - check!
Axle Stands - check!
10mm spanner - check!
10mm socket on 6" extesnion - check!
12mm spanner - check!
12mm socket and various extensions - check!
14mm socket - check!
Hammer - check!
Vice - new manifold so don't need!
Long flat bladed screwdriver - check!
High pressure water or air supply - new manifold so don't need!
Large vocabulary of swear words - check!
Also have o2 sensor socket, PlusGas, a mechanically minded friend to help...before i start this (hopefully this weekend, if not then next weekend) can anyone recommend anything else i may need during this pre-cat removal? I'll be using a new manifold since it only cost £130. And also replacing as many stubborn bolts as possible before starting...luckily many were replaced when My exhaust was being fixed
Possibly new gaskets and new nuts and bolts just in case you ruin the thread of a stubborn one.
Quote from: "GT4thomas"Possibly new gaskets and new nuts and bolts just in case you ruin the thread of a stubborn one.
New gaskets come with my new manifold I think, i removed some of the stubborn bolts today, i managed to take the annoying ones from the heatshield without ruining the threads (did break the bolts for it though which i need to buy, just waiting on my manifold and i can start ^_^
But by stubborn one do you mean a different bolt?
Have no experience myself, but I tend to recall from many a past thread, that it is worth getting the proper Mr T head-to-manifold gasket.
I have removed heat shields for access and never put them back. Does get warm back there, as my pipes are running bareback. I quiet like it that way. Even gave them bit of a rub with the Autosol. s:D :D s:D
The exhaust manifold to head gasket that comes with some eBay manifolds I understand has not been suitable in service and a Toyota gasket has been used.
I managed to damage some of the cylinder head studs and so replaced those.
The nuts for the studs are a tri lobal locking type and should be renewed.
The gaskets between the manifold and the cat should also be renewed.
I stripped the cat and heat shields and power wire brushed them,they came up shiny, I believe they are a low grade stainless steel. Refixed them with stainless steel nuts, bolts and washers ( from Screwfix) and refixed the shield on the bend with a jubilee/ worm drive clip.
Many remove the OE manifold as you intend and also the heat shields .
I chose to keep as near OE ( minus the precats) as I could.
Mmm i'm gonna keep the heat shield, not going to wrap the manifold, seen cases of where people see cracks in the manifold, I managed to remove the heat shield without ruining the threads, hopefully i wont damage anything but will deal with that as it happens, hopefully gonna start tomorrow
If your pre-cats have gone, are you able to salvage any of the engine such as the top end? I've just bought a 2001 mr2 which has white/blue smoke and is running rough. I've just ordered a 22m oxygen socket so I can check the pre-cats.
The 2001 model piston oil control rings, particularly in cars with poor oil change history, have been generally accepted as the cause for excessive wear in the cylinders leading to excessive oil consumption which breaks down the precats material which can then be sucked back into the cylinders exacerbating the situation.
Until very recently an associatevMatt Performance offered rebuilding of the engine.
Unfortunately this is not now the case.
However if you look at MattPerformance in the associate section you will see a schedule of work that was undertaken for the rebuilds offered for varying engine conditions.
You will see that the engine can be rebuilt even after severe wear has occurred.
Alternatively have a look at an engine exchange from a donor car as described under 2zz in the maintenance and troubleshooting section.
Sorry that you have not had the best start to MR 2 ownership but hope that you had planned to do some work in getting your car into good condition.
OK, just spent the day replacing the manifold.....quite inpressed with myself but i'm having one problem....the 5 bolts which connect the gasket...i can't get the last one in...the other 4 are in fine (took a lot of annoying lining them up to fit....anyways anyone had any problems fitting the manifold and gasket to the car? it's one of these m http://www.ebay.co.uk/itm/TOYOTA-MR2-RO ... 4897.l4275 (http://www.ebay.co.uk/itm/TOYOTA-MR2-ROADSTER-1-8-DECAT-EXHAUST-MANIFOLD-00-07-MF6110-/310256048298?_trksid=p2054897.l4275) m
I havn't put in my o2 sensors yet to see if it works! but i'd prefer to get the 5th bolt in if i can first....any tips?
These must be the head to manifold studs.
The studs should first be screwed into the head.
If any came out when you removed the OE manifold or you are replacing the studs screw these in by hand first ensuring all threads are clean.
The studs can be tightened home by putting two ( old )nuts on the stud and locking the nuts together with two spanners. Then tighten the stud, a torque wrench can be used for this.Then remove the nuts with the two spanners.
When all studs are in then offer up the manifold . This should go straight on.
If not you will need to adjust the holes in the manifold.
To do this you need to determine where the interference is.
This can be done with a strip of masking tape ( light colour) applied over the face of the manifold that faces the head.
Find something sticky and dark coloured, engineers blue is the traditional thing to use. But improvisation with a dark grease such as Copaslip or a marker pen or a dab of paint will do the job. Apply the marker to the end of the studs and again offer up the manifold and press the manifold against the studs.
With a modicum of luck when you look at the manifold you will see the marker where the manifold holes need opening up.
I suggest a round file for this as the idea is to remove the minimum material necessary
In short you need to fit the manifold to all 5 studs in the one go.
Clean up before fitting the manifold and beware that no swarf or material enters the exhaust ports on the head
ADDENDUM:
The above is engineering practice for aligning items where no template is available.
In this case you have the old manifold and the new gasket!
The gasket is probably easiest to use, so place the gasket on the face of the new manifold and accurately locate the gasket with the holes that you know are in alignment with the studs. This can be done for instance with two drills or two bolts of suitable size. You will then see the error in position of the one hole( maybe more slightly out also). Mark the manifold with a marker pen or similar. Remove the gasket or it will get damaged. Then file out the hole/s as required. You can use the gasket to check progress but be careful that it isn' t damaged.
The new flange is likely thicker than the OE flange and so take care that you open the hole out square to the flange face.
If you have a Dremel tool this may speed up the process.
As above take care to remove only what material is necessary and use eye protection when using any power tool.
Quote from: "Joesson"These must be the head to manifold studs.
The studs should first be screwed into the head.
If any came out when you removed the OE manifold or you are replacing the studs screw these in by hand first ensuring all threads are clean.
The studs can be tightened home by putting two ( old )nuts on the stud and locking the nuts together with two spanners. Then tighten the stud, a torque wrench can be used for this.Then remove the nuts with the two spanners.
When all studs are in then offer up the manifold . This should go straight on.
If not you will need to adjust the holes in the manifold.
To do this you need to determine where the interference is.
This can be done with a strip of masking tape ( light colour) applied over the face of the manifold that faces the head.
Find something sticky and dark coloured, engineers blue is the traditional thing to use. But improvisation with a dark grease such as Copaslip or a marker pen or a dab of paint will do the job. Apply the marker to the end of the studs and again offer up the manifold and press the manifold against the studs.
With a modicum of luck when you look at the manifold you will see the marker where the manifold holes need opening up.
I suggest a round file for this as the idea is to remove the minimum material necessary
In short you need to fit the manifold to all 5 studs in the one go.
Clean up before fitting the manifold and beware that no swarf or material enters the exhaust ports on the head
ADDENDUM:
The above is engineering practice for aligning items where no template is available.
In this case you have the old manifold and the new gasket!
The gasket is probably easiest to use, so place the gasket on the face of the new manifold and accurately locate the gasket with the holes that you know are in alignment with the studs. This can be done for instance with two drills or two bolts of suitable size. You will then see the error in position of the one hole( maybe more slightly out also). Mark the manifold with a marker pen or similar. Remove the gasket or it will get damaged. Then file out the hole/s as required. You can use the gasket to check progress but be careful that it isn' t damaged.
The new flange is likely thicker than the OE flange and so take care that you open the hole out square to the flange face.
If you have a Dremel tool this may speed up the process.
As above take care to remove only what material is necessary and use eye protection when using any power tool.
Thanks very much s:) :) s:) i'll try sourcing new studs first, I noticed when I replace the gasket that there is now no place for the heat guard to be replaced, I didn't heat wrap it because I read up on some cracking the manifold...how much of an issue will it be driving without any heat shields/guards?
I've got loads of spare nuts and bolts but I bought them so long ago I can't take them back now lol.
Like you, I wanted to make sure I had everything in case I had any issues during the process.
I found it quite strange that the manifold to engine nuts have been changed:
(http://img.tapatalk.com/d/14/08/10/tagu9y2a.jpg)
When you removed the manifold nuts did they came off with the studs attached?
If so you may be able to rescue the studs.
Put the studs into a small container and soak them in Plusgas or similar.
Then put the nut in a vice with the stud vertical above it.
Put two nuts onto the other end of the stud and tighten them together.
Put a spanner on the lower nut and undo the stud from the original nut.
New nuts should be used for refitting the manifold these are a self locking type.
The new nuts Bluesmoke has do not appear to be self locking.
As for the heatshield I understand some members run without that refitted.
Of these some have heat wrapped the manifold and some haven't.
There is a recent thread on that subject.
Your car will run with or without the heatshield and with or without the heat wrap.
I doubt you will notice a huge difference either way within the restrictions applicable on your island home. s:wink: :wink: s:wink:
Quote from: "Joesson"When you removed the manifold nuts did they came off with the studs attached?
If so you may be able to rescue the studs.
Put the studs into a small container and soak them in Plusgas or similar.
Then put the nut in a vice with the stud vertical above it.
Put two nuts onto the other end of the stud and tighten them together.
Put a spanner on the lower nut and undo the stud from the original nut.
New nuts should be used for refitting the manifold these are a self locking type.
The new nuts Bluesmoke has do not appear to be self locking.
As for the heatshield I understand some members run without that refitted.
Of these some have heat wrapped the manifold and some haven't.
There is a recent thread on that subject.
Your car will run with or without the heatshield and with or without the heat wrap.
I doubt you will notice a huge difference either way within the restrictions applicable on your island home. s:wink: :wink: s:wink:
Had to buy new ones, too hard to fit properly without putting them in fisst, managed to get some in though, seems secure now, hopefully they won't take too long to come to my 'Island home' lol
Before
m http://postimg.org/image/gpk7hb1dv/ (http://postimg.org/image/gpk7hb1dv/) m
After
m http://postimg.org/image/dnottlyv7/ (http://postimg.org/image/dnottlyv7/) m
Seems to be driving ok was a little smoke to start with from the PlusGas which is expected but seems fine now, engine sounds a little better too but no noticeable change in power as predicted
I agree with what has been said on here before: It would be a shame to cover it up!
Hope all continues to go well for you and your 2.
I've just got round to removing the oxygen sensors on the pre-cats to discover the left 1 had a light coating of soot but the right 1 was caked in oil.
Any ideas to what would cause this before I start taking the head off??
Neither side of the pre-cats had any sign of a matrix inside and I don't have any history to know whether or not they have been removed a previous owner.
Surely some fragments of the matrix would still be seen if the part has failed? Any info would be much appreciated.
I saw my complete pre-cat matrix before removing it.
I have also seen photographs of pre-cats that have started to break up when there was still some honeycomb material to be seen.
If there is no sign of any honeycomb material at all then it is likely that this was removed at some prior time.
The soot coating on one sensor and oil coating on the other would be indicative of what is exhausting from the relevant cylinders.
The soot could indicate a poor fuel/ air mix but the oiling indicates wear.
Firstly, check your spark plugs.
Are these similarly two sooty and two oily?
What year is your car and what mileage?
Has the car been using oil?
The cars built 2003 to 2006 had a series of changes to the pistons and oil control rings each to improve there function.
Engine wear typically increases with mileage.
Frequent topping up of the engine oil is an indicator that the engine is worn, typically an ovalling of the bores causing oil to be drawn from the sump, burnt during combustion and exhausted via the pre-cats which when contaminated with oil begin to break up.
In certain modes the engine rebreathes the exhaust introducing the abrasive precat material into the engine and exacerbating the wear.
If this fits the profile of your car then I suggest that a previous owner has removed the precats, either as a preventative measure or an attempt to cure the problem.
A test of each cylinder compression will give you a good indication of the condition of the engine.
If the compression readings are low or differ greatly then excessive wear of the pistons is most likely.
This may not be the scenario you wanted to hear but is unfortunately sometimes the case.
There are remedies however which vary from partial to full rebuilds or replacement of a similar or higher performance engine.
Very much information can be found on here via "search" and there are good people on here that have been where you are and have worked through a solution that I am sure will offer advice as you uncover your mysteries.
Thanks Joesson, I will be checking the sparkplugs tomorrow and be looking to get the head off to see whether the head gasket is gone or for some more clues to the white smoke and oil.
I was after a project and I paid £400 for 2001 which has a smoking engine, but the rest of the car is almost perfect, a small scratch on drivers door and a small chip to the front bumper. I'm in no hurry to get her on the road so will plan to work through the engine and rebuild it if viable.
Just a quick one, the gasket rings for pre cats to main cat pipe, they're coated with paste by the looks of it, so you don't need to do anything else when replacing them, right? Just sit them in place and bolt everything up?
Nothing else required. The furry bluey-green paste does the business.
Go slow and even across the three amigos in several passes to keep everything square. Torque is, um.... in the region of 46 ft lbs.
Excellent recall spit!
46lb ft in old money
62 Nm for the metricated.
Metricated I am! Will do this tonight. Then run the car up to temp so that the paste can do its thing.
Blue smoke and harvey718 I suggest you have a look at the new members section, BillRitson has a 2 with 217k miles since he had it from new.
For the first 120k the oil and filter was changed every 5k!
Quote from: "Joesson"Blue smoke and harvey718 I suggest you have a look at the new members section, BillRitson has a 2 with 217k miles since he had it from new.
For the first 120k the oil and filter was changed every 5k!
I saw it a few days ago. Amazing!
I've researched this issue and it seems most failures occur to the pre cats on early pre face lift cars. I have a 2004 with 27000 miles on clock. Don't know whether to remove the pre cats. It appears most people with cars pre 2003 have this issue?
I suggest that BillRitson ( see newcomers) got it right.
His car must have been regularly used and regularly had an oil and filter change.
I am of the opinion that the precats fail after excessive oil consumption and exhausting the burnt oil via the precats causes there break down.
Your 2004, will have some of the piston and oil control ring modifications that Toyota made post 2003 to end of model manufacture. With reatively low mileage and hopefully regular oil and filter changes your car is less likely than mine (2002/ 54k) to suffer oval bores.
I decided to remove the precats. It was not a difficul process, I refurbed the heat shields while doing it.
There has been no problem with subsequent MOT emission tests and for sure my precats cannot damage my engine.
I wouldn't t advise you to retain or remove your precats.
I would advise that you regularly change the oil and filter.
Whatever your choice enjoy your 2.
Thanks for the info. I intend to change my oil regularly and use the car daily . Hopefully all will be ok with the pre cats . I've just had the car serviced. And will ensure it's done often
Just reading this now for the first time, very good write-up
food for thought...
Thought I'd read on down through the posts, have a couple of questions now (apologies if they've been answered, I read through the first 2 pages and my eyes are going blurry and better get back to work so thought I'd post):
1 - taking everything into account other than cost, would it be better to remove the precats or buy a new manifold?
2 - If its buying a new manifold, can anyone recommend a few to look at, including performance ones?
3 - If I removed the pre-cats, does it affect any tests and would I have to inform anybody like insurance company, tax etc.?
Dale
Quote from: "dkirkwood89"Thought I'd read on down through the posts, have a couple of questions now (apologies if they've been answered, I read through the first 2 pages and my eyes are going blurry and better get back to work so thought I'd post):
1 - taking everything into account other than cost, would it be better to remove the precats or buy a new manifold?
2 - If its buying a new manifold, can anyone recommend a few to look at, including performance ones?
3 - If I removed the pre-cats, does it affect any tests and would I have to inform anybody like insurance company, tax etc.?
Dale
I Just bought a new manifold & Manifold bolts (as some don't come with new bolts), cost me £120 for the manifold and about £30 for the 6 manifold bolts
m http://www.ebay.co.uk/itm/TOYOTA-MR2-RO ... 483cb398aa (http://www.ebay.co.uk/itm/TOYOTA-MR2-ROADSTER-1-8-DECAT-EXHAUST-MANIFOLD-00-07-MF6110-/310256048298?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item483cb398aa) m
And I bought the bolts from this site
l viewtopic.php?f=57&t=50500 (http://mr2roc.org/phpBB3/viewtopic.php?f=57&t=50500) l
If you choose to replace the manifold, the heat shield will not go back into the non-genuine manifold, i've never had any problems with this or heard of anyone who has had these problems, been using this manifold for over 6 months without any problems, other tip would be when removing the diaper under the car, you only need to remove the rear diaper, and half of the middle diaper, you don't need to crawl all the way under your car to completely remove the middle diaper
I'm hoping that Wabbitkilla will read this and post the pictures that he took, but I've just replaced my manifold and not a moment too soon.
The precats had just started to breakdown and any longer and that would be knackered main cat and possibly knackered engine!
My car doesn't burn any oil, nor did it use any generally, but the precats we still starting to break down.
Get them out ASAP!
So do you think that engine begins to burn oil due to poor maintenance and the oil changes not being carried out regularly? I have seen some Mr2s on here with mileage well over 100,000 and still on same engine. Most of these have been serviced regularly
Having bought my 2 a couple of months ago and added another 2k to the 17 it had already, I saw this thread about pre-cats and the potential damage. Decided to go down the route of an after market manifold.
Getting the old one off . . what a nightmare! Ended up cutting the heat shield on the right hand O2 sensor hole as I didn't have an O2 socket and, having cut my shiny new 22mm DD socket and found it didn't work, I was in a no nonsense mood. Most of the bolts were so rusty they broke off. The bottom flange wasn't too bad and the top was easy. However it took me a good few hours of digging deep in my box of swear words to get it off and out. Five minutes later the new one was in, the O2 sensors removed from the now easily accessible manifold. A short while after that it was all buttoned up . . I say buttoned but quite a few of the bolts holding the plastic bits underneath had also sheared off due to the excessive rust. Never mind, that is what tie wraps are for hey? Off I went down the road smoke pouring out of the engine bay as all the old WD40 burnt off s:D :D s:D As I slowed for the roundabout a horrible noise like something dragging on the ground made itself heard. I pulled over in the petrol station . . smoke still coming from the back s:flame: :flame: s:flame: whoops. Anyway nothing to be seen so I slowly drove back home with an awful noise coming from my lovely little car. By this time I was thoroughly sunburnt and hurting so I called it a day.
This morning I carefully got dressed and rigged up a sunshade over the back of the car and slathered myself in factor 40. Removed the plastic stuff from underneath and had a look. The 2 into 1 section's heat shield was right up against the cross member where the bolt hole is. I tried slackening joints and levering to no avail. Right that heat shield is coming off! No I am not says the heat shield. A war ensued. I removed one nut and bolt, cut off three others and left the stupid one in between the two pipes where it was. I managed to wriggle and jiggle the heat shield until I had some daylight showing between it and the cross member. Using a screwdriver as a podger I managed to line up the holes in the tin ware and get a new bolt in. Now the opposite side which had been the offending area . .another bolt. So far so good. The bracket things had lined up reasonably well. Now to the two that join it to the tin ware on the next section rearwards. Podged one set of holes into alignment and bolted. The other was nowhere near lining up so stuff it. It'll have to stay like that.
Checked the clearance was still there . . . . yeah. Off the ramps and a quick blast up the road for a few metres. OK reverse it back . . OK Oooh seems like it might have just enough clearance. Back on the ramps to stick the plastic stuff on again and take it for a blast on the road. Down to the roundabout accelerating hard and braking hard. . . . .sweet sounds. Round the roundabout not quite getting my knee down but hard -ish . . . OK. Back home reverse it hard and brake . . OK. Seems I may have done it.
If I haven't then the next stop for my little car is a visit to the race workshop where I can get the oxy-acetylene onto that fifth bolt. Heat shields off and exhaust wrap on. That will definitely sort it. But for now the main thing is I don't have any pre-cats or any lingering doubts about whether the garage mechs got all the ceramic out of the old manifold s:D :D s:D
That' s a nice low mileage "2" you have found for yourself.
The pre emptive surgery should do no harm other than perhaps aggravate symptoms of moditis !
Thank you, yes it is a lovely low mileage example. Not the colour I would have chosen and not the trim option I would have chosen. But the mileage! That trumped all other considerations. Well worth the aggravation of the modification to keep it in tip top condition. As for moditis? I am not addicted, I can control it and give up any time I want lol . . . .ooh MAFmod hmmmm
Thanks I'm going to give it a go but I am going to be prepared!
Does anyone know what bolts sizes I will need as I may as well replace them as a go?
Also which gaskets do I need?
Thanks again
Just done mine, one manifold bolt took me 5 fricking hours to get undone!!!
I also noticed that there was no gasket rings between the main cat and manifold!
I have ordered a new manifold gasket and ring gaskets.
Need to get a new stud and bolt thern reassemble,
someone said to dip the studs in copper grease so going to do that.
Question.... Is the plastic under panel underneath the engine bay in 2 parts as I only seem to have one piece under the oil sump?
5hrs?!? One religious figure on a pedaled vehicle.
Good man for sticking with it.
Bottom panel is indeed in 2 parts. The "nappy" on the rear covering the cat and the middle bit covering the sump
Question?
Now that I have done the De-cat mod what if the Main cat started to break up?
It now would have a straight path into the engine!
My main cat was replaced earlier this year as Mr T said there was a rattling from the exhaust (not Manifold) and suspected the main cat was breaking up!
Sorry if I've missed it but read pages of this thread. Is there a list of the parts required as part of this process (seen people mention replacement gaskets and bolts)? Going to tackle it in the next couple of weekends, wish me luck.
Thank you
All the exhaust gaskets and if you're lucky the bolts are reusable.
What I would do is spray the crap out of the manifold bolts (at block and top of cat pipe) and see if you can undo them. If they come undone, saves you almost 70 quid in bolts.
Quote from: "shnazzle"All the exhaust gaskets and if you're lucky the bolts are reusable.
What I would do is spray the crap out of the manifold bolts (at block and top of cat pipe) and see if you can undo them. If they come undone, saves you almost 70 quid in bolts.
Cheers, just going to take it steady and come back to it, car is in the garage for winter now anyway.
Found a list on Facebook if it's of use for future reference (Credit to Edward Banzan):
T17173-22010 manifold gasket x1 £20.32. The nuts are T90179-08228 x5 £1.14, CAT gasket £4.15 T90917-06066 X2, three amigo nuts T90179-10070 £1.85, burrows Toyota doncaster
[Mod]a quick heads-up - crush gasket part number is 90917-06065, not 06066 as stated.
That's it! Also bear in mind your exhaust to cat bolts (with springs) might be too far gone to re-use.
They're a stupid amount per bolt. I believe 12 quid each excluding spring.
Hi Guys,
I'm new to the site having just bought a mk3, however the first thing I noticed is the precats are well and truly knackered!
The car seems to be running fine however with a slight tapping noise from the engine at over 4000 rpm, would this sound be because of the damaged precat?
Don't know wether to decat it of send it back to the lad in bought it off and look for another.
Cheers
Tough one Kitch. But given the evidence suggesting engine damage from pre-cat failure, which is caused by oil control rings failing, there's enough grounds to send it back I reckon. Unless they take it back, rebuild the block, replace the manifold (or knock the pre-cats out) and give it back
I was lucky enough to have been bought an MR2 roadster for a 'special' birthday 6 months ago. It is a 2002 pre-facelift model - a fantastic car and I've loved every minute of driving it.
Like anyone with a new toy, I soon found the mr2oc online and read all about pre-cat failure and piston rings and began to think my car would be a liability. I check the pre-cats regularly (all intact) and it hasn't used a drop of oil in 7,000 miles (now done nearly 100,000). all the online forums and buyers guides state that the piston rings were improved for the facelift model and they all recommend that this is the one to go for. I was worried - was my car a lemon?
The I found the Toyota online parts catalogue (toyota.epc-data.com) and found that the piston rings, pistons, short block and exhaust manifold were all updated well before the facelift model was launched.
For example, the parts number for piston rings for a car built between 12/99 and 11/01 is 13011-22090. The same part for a car built between 11/01 and 09/05 is 13011-22150. The facelift cars were built from 08/02.
So, basically, a pre-facelift car built from November 2001 has exactly the same piston rings, pistons, short block and exhaust manifold as the facelift model.
This is backed up by the mr2roc log of pre-cat/engine failures. It has details of 20 cars that have destroyed their engines. 18 of them were first registered 1999-2001. Of only two cars registered 2002/3, one blew up on a track day so I'm not sure that counts... So at least 90% of engine blow-ups have been in cars built before 2002.
If you're not sure when your car was built, enter your VIN on the toyota.epc-data.com website and it'll give you the build date. If you've got a pre-facelift care built after November 2001, its engine is identical to the facelift model. The only difference is, you probably didn't have to pay as much for it and it's a lot better looking...
I think this is an important point - most buyers guides out there advise that the face-lift is the mechanically stronger car and many pre-facelift cars are undervalued as a result. It seems most motoring journalists are happy to assume this is true without taking the trouble to investigate a bit further.
I will probably still remove the pre-cats; I get that they're a liability. So far I've changed the gearbox/diff oil (Redline MT90), engine oil (fully synth 5/30), filters and put new tyres all round.
Great car. Great owners club - but stop dissing the pre-facelift!!
Until the very last few cars, the oil control problem in the basic piston design was never fixed. So, in a way you're right, the Facelift engine is no better than the pre-facelift engine. Yes they did 'upgrade' the rings, but the basic piston design flaw remained.
Trust me, I've had quite a few engines in bits. If a car has always had regular oil changes, it can dodge the bullet. Many do.
Sounds like you've got one that has always been properly looked after. I came across one car that was one of the first sold in the UK. Over 130,000 miles and one owner. Engine was mint. Mind you, the sub frame and gearbox weren't.
I don't think you'll find many of our members 'dissing' any of these cars. We're enthusiasts, not journalists, and we know a lot more about them than any journo.
I agree - my 'dissing' comment related to the buyers guides - Autocar, Pistonheads etc. - which tend to say 'buy the facelift - you won't have a problem'. We know it's not that simple but it would be good if the club was clear about when engines specs were changed - i.e. make it clear that it was well before the facelift.
I know I've got lucky (so far) with my car. It's got a full service history and both the sub frame and gearbox are good.
I have a long outstanding task to revisit the buyers guide I wrote on here. So that note is something worth adding.
However....
There is also evidence to suggest that the oil control ring changes as well as the newer piston design was introduced long before we think.
Just not in the UK...
So going off part numbers may not show all.
There's even evidence that cars who had warranty rebuilds by Toyota before 2006, already have the latest pistons, which reportedly only came out in 2006...in the UK....
Blame the US litigation culture for that one,or rather the UK's lack of it.
The main reasons for going to facelift (especially post-2004) are more around safety and bracing, as well as the styling (taste-dependent).
The pre-cat story is, as written earlier here, fraught with half-truths.
It's important we don't scare away people who want to, get, or can only afford pre-facelifts.
Had a quick check today on the pair of mani-cat gaskets part number. It seems to have been misquoted earlier in this thread - post edited as follows:
Quote from: "Bossworld"CAT gasket £4.15 T90917-06066 X2, three amigo nuts T90179-10070 £1.85, burrows Toyota doncaster
[Mod]a quick heads-up - crush gasket part number is 90917-06065, not 06066 as stated.
06066 relates to a gasket used elsewhere in the Toyota range.
Can someone cross-check this for me and confirm? If I'm wrong I'll dive in and re-edit the edit!
Ta
Quote from: "spit"Had a quick check today on the pair of mani-cat gaskets part number. It seems to have been misquoted earlier in this thread - post edited as follows:
Quote from: "Bossworld"CAT gasket £4.15 T90917-06066 X2, three amigo nuts T90179-10070 £1.85, burrows Toyota doncaster
[Mod]a quick heads-up - crush gasket part number is 90917-06065, not 06066 as stated.
06066 relates to a gasket used elsewhere in the Toyota range.
Can someone cross-check this for me and confirm? If I'm wrong I'll dive in and re-edit the edit!
Ta
toyodiy says you are correct - m http://www.toyodiy.com/parts/p_E_200208 ... ?hl=17410B (http://www.toyodiy.com/parts/p_E_200208_TOYOTA_MR2_ZZW30L-AKFQHW_1702.html?hl=17410B) m
Quote from: "spit"Can someone cross-check this for me and confirm? If I'm wrong I'll dive in and re-edit the edit!
Ta
Might as well remove my post remove it, I literally C&P'd from Facebook after a Google Search s:? :? s:?
Quick one folks,
I've been to view a really nice mr2, well, much nicer than my current one at least.
It has had a lot of work done to it and is well look after but has a fairly decent mileage on the clock, trouble is the fella doesn't know if the precats have been removed or not.
Now, I'm no mechanic so I think trying to find out is above my level, but the car needs an o2 sensor replacing, would this be related to precat removal?
Cheers!
You'd have to take a spanner to a car that you don't own, to find out. If the sensor that needs to be replaced is on the manifold (not the main cat), you will be able to see the top of the catalytic matrix when it's removed.
If the owner of the car doesn't want you to do this, it's not a big deal as you'll find out soon enough and (if the pre-cats are still there) getting them out is not a deal-breaker.
Odds are if it's had lots of work and been well looked after, the pre-cats will be gone.
You might even want to put a decent de-cat manifold on?? Even paying a mechanic to do it might well be worth it if your really like the car.
Not a bad idea actually getting a new de-cat.
Either way, the car is an import and touching 100,000 on the counter. So I'd like to think that the pre cats are looooong gone! But the owner won't have a problem with me taking a spanner to it, either myself or a mechanic.
Thanks for this very useful post. I, too, have a pre-facelift. Mine is proper pre-facelift, being on a Y plate. It's with the garage having the precats ripped out and a new manifold bolted into place.
Quote from: Chase27 on September 6, 2018, 21:18
Thanks for this very useful post. I, too, have a pre-facelift. Mine is proper pre-facelift, being on a Y plate. It's with the garage having the precats ripped out and a new manifold bolted into place.
Just to clarify your post, if you're having a new, precat-less manifold fitted then I assume "having the precats ripped out" just means they're removing the standard manifold? They're not actually removing the precats from the standard manifold as well as replacing it??
Sent from my iPhone using Tapatalk
You're right. That was imprecise language. I had the old manifold replaced with a stainless steel unit, new spark plugs, new air filter, oil change.
Feels great. Rorty engine sound and a definite positive tweak power-wise.
But best of all, I can relax about pre-cat disintegration...
Quote from: Chase27 on September 11, 2018, 10:39
You're right. That was imprecise language. I had the old manifold replaced with a stainless steel unit, new spark plugs, new air filter, oil change.
Feels great. Rorty engine sound and a definite positive tweak power-wise.
But best of all, I can relax about pre-cat disintegration...
Good stuff! Assumed that would be the case but just checking the garage weren't trying to have you over.
Enjoy!
Sent from my iPhone using Tapatalk
Cheers
Hi,
To do with pre-cats.
I have removed mine and have also fitted a new exhaust manifold and a twin pipe exhaust system - both sourced from "Mr2" Is there any liklihood of my compromising the MOT regs re emissions?
Many thanks.
Should be fine as long as you keep the standard cat and everything else in good order.
Quote from: Hamezi on October 8, 2020, 11:47Hi,
To do with pre-cats.
I have removed mine and have also fitted a new exhaust manifold and a twin pipe exhaust system - both sourced from "Mr2" Is there any liklihood of my compromising the MOT regs re emissions?
Many thanks.
None at all once the main cat is up to temp it takes care of everything.
Believe pre cats where to pass more stringent emissions laws elsewhere say california
What ^^^^^^^ they said.