Sorry to add to the many Pre-Cat posts already on here but I'm hoping some of you with the experience & brains can clear some things up for me. ...
Don't worry I've spent a long time searching and reading already s:) :) s:)
I've got a 2002 2 with 27k on clock and am obviously V wary of the pre-cats (more so as it's pre 2003)
These are the options I would seem to have: (It would be good to hear how many people have chosen to do what so I can get an idea)
- Best & cheapest choice seems to be to gut them but I've read bad things about emissions after doing this. I see alot of members on here have gutted theirs... does everyone get problems with emissions after doing this? (Having to rag the engine before the MOT..etc)
- Leave pre-cats - I am a usually a believer in "If it aint broke, Don't fix it"... (but not sure if i am in this case!) Are many people leaving theirs and hoping for the best?
- Change to a CHE manifold or similar. Is there any negatives with the CHE? (I'm not that mechanically minded to be honest s:? :? s:? ). Plus does this sort of change make much difference to insurance?
Thanks in advance for any advice!
Personally, I have a '00 with 75k. I have left the precats in and take the 02 sensors out every couple of months and have a look. I also keep an eye on the oil consumption. That said, I am sure someone will tell me that the precats break up very quickly, or I am mad.
I'm leaving mine in. The reasons for this are:
1. I guesstimate the failure rate to be around 1% from the evidence I've seen and heard about.
2. Post de-precatting problems others have experienced.
3. In all the posts I've read where people have de-precatted they are always in A1 condition.
sods law says if you ignore and easily prevented problem, yours will be teh 1% that goes bang
lets hope not
interesting side question?
couple of years ago MR2 specific 1zz engines were dirt cheap, theyv'e doubled in teh last 2 years, why?
I suspect teh demand from people with dead engines.
Gutted mine at a year old when still in warrenty. Never had an issue since and have passed two MOT's with very low emission values s:wink: :wink: s:wink:
That's actually quite promising to hear it's probably only around 1% ...If that's the case then I'm quite tempted to leave and hope for the best s:) :) s:)
I would have said it was way way higher than that after reading all the posts on here... but as someone else said - forums like this are a magnet for people with problems/wanting advice so can make it sound much worse than it really is.
you might want to go check SC as well
the percentage over there is very high
personally you'd be mad to risk it
I forgot #4:
Sheared manifold bolts.
Quote from: "markiii"sods law says if you ignore and easily prevented problem, yours will be the 1% that goes bang
That's exactly what happened to me, I was leaving it 'till the summer, and they went bang on boxing day! s:roll: :roll: s:roll: I'll also need a new engine soon as it's losing a lot of oil:(
I'd recommend doing it asap.
BTW. Mine was a 2001 model with around 40 on the clock.
I don't think anyone has been unable to pass MOT emissions tests because of precat failure. As long as the garage does the test properly and warms the engine up first.
Our engine is shared with the celica and corolla.
They don't have precats and don't have a problem with emissions.
Gutted mine when one year old...first MOT this Saturday!!
Certainly not doing mine (04) while it still has 6 months warranty, but after that will seriously consider it. unless I extend the warranty, decisions decisions !!
I would suggest to those concerned about gutting and MOT failure to either get a che manifold or get hold of a spare manaifold and gut that.
if you fail mot, swap them back, no big deal
at least your not risking your engine 11 months of teh year
Is it a serious risk on 05+ cars though? Reading around it appears the majority of failures are 00-02?
T
Dan had 2 in succession go on his 03 1 with less than 1000 miles on it.
never heard of an 05 failure yet but then they are all going ot be quite low mileage
I'd still remove them on an 05, aside from teh obvious plus points are a fraction more power and a less boring exhaust noise
My last 2 passed 2 MOTs with no precats and the tester didn't have a problem with emissions on either occasion. I certainly felt happier with them removed.
I found that if you combined the gutting work with doing something else like changing the exhaust, it was pretty good in terms of hours spent per jobs done.
Gutted my 02. Bought my 06 with 7 miles on it and put on a che asap.
Simple really, as dirty Harry said "do you feel lucky punk?"
Three types of people on here;
1/ gutted, precats are gone and are worry free. s:D :D s:D
2/ non gutted, precats are still in, blase about it, not worry free. s:?: :?: s:?:
3/ gutted, because they left the precats in and engine went bang. s:cry: :cry: s:cry:
There is good advice on this forum, from a lot of clever people who know the 2 well, i chose to listen s:) :) s:)
im in a similar situation- 03 model 52 plate with 33k on clock.
have extended warrenty atm so have a bit of safety with that- getting big service done in a month or 2 along with and just before warrenty comes out will check pre cats. if badly damaged --> mr t and kick up a fuss, if no damage CHE manifold.
risk doesn;t seem worth it keeping them in IMO, check with insurance company to see affect on premium thou.
No effect on my premium with More Than
Gutted mine at 10k, admittedly not under warranty, but 100% peace of mind.
imho you'd have to be crazy not to. Esp considering the length of time you can be off the road and the arguments with MrT to get your engine fixed.
I couldn't disagree more with some of the opinions expressed on here.
I'm now firmly convinced that pre-cats are not the cause of engine failures and I will not be removing mine.
This is an important issue which has been covered before, but in the interests of presenting a more balanced view I've just posted a new thread - see "Pre-cats The Alternative View".
Markiii. Have you lock my thread becuse you diasagree with the opinions expressed?
I think this is an important issue wich deserves a thread of its own.
Please re-open it.
[ADMIN] Mike, I've locked your other thread as I see no point in starting yet another thread just to refute the opinions in thisone, just keep it all in one place. [ADMIN]
from a personal point of view if you 'd rather take advice from Toyota rather than "a few enthusiats on teh internet" (your perogative) why are you here, we have nothing of value to add s:wink: :wink: s:wink:
if it was purely because I disagreed with it, I would have just deleted it. (Well actually I wouldn't because I'm not like that, but you see my point)
Markiii. You might see no point in allowing people to discuss this issue in its own thread, but I disagree and I think others might support my view.
Please re-open the thread
Mike, how often does your average service manager/ toyota mechanic work on, as you pointed out, the low volume model of mr2?
If you wish to believe verbatim what a company who wants your sales, servicing and loyalty for money over free advice from people who know the car inside out, good luck.
Quote from: "mikevernon@talktalk.net"Markiii. You might see no point in allowing people to discuss this issue in its own thread, but I disagree and I think others might support my view.
Please re-open the thread
[ADMIN]
I didn't say it was open for debate, general rule we discourage duplicate threads, you were refuting opinion in this one, so discuss it here. We have enough Precat threads as it is, teh sticky was created to discourage that.
the sticky is based on ancedotal evidence gathered over 5 years experience. Yours is is hearsay. Get me an official statement from Toyota to that extent and I'll sticky it. [ADMIN]
Agree with the post a few ones up... I did mine while I was changing the exhaust and a dead o2 sensor!
I changed the exhaust using the 'cat out' method so it wasnt much more work to get the manifold off anyhoo!
Mine were in perfect condition when i removed them - 02 with 29k on the clock. Removed cos it was off and it was fun to hack at them with the drill!!
As regarding Mikes response in the other thread...
I agree, concensus now suggests the cylinder wear and oil consumption on earlier engines were what appears to be the initial cause of engine failure.
The fact that it affects the pre-cat material to such affect and the consequent pre-cat break up and ingestion by the engine causing even more damage is a worry.
It was to me a worry i would rather live without. We all have to make our own choices in life and live with the consequences. Taking the pre-cats out doesn't affect the legality of the vehicle as it still passes European emmissions regulations. MoT's seem to be a doddle so long as your main cat is not clogged by pre-cat material or damaged by excessive oil use.
You are extremely lucky to find three Mr T dealers with such knowledge of the Roadster. From experience i haven't found one who can even put the right amount of air in the tyres. Who says there's a cover up? Only that there have been a few unfortunates who have suffered engine failure. Their sorry tails of trying to get Mr T dealers to fix the problem whether it's piston/ring cause, precat failure or other proves to me that prevention is better than being stuck off the road while some faceless person decides IF they want to fix your car.
Toyota are not alone in this, i and friends have experienced problems with engines at the hands of VW, Ford, Vauxhall, Alfa Romeo. If we had known a simple procedure to cut the risk, we would have taken it.
As for me, it's an 03 facelift car produced on the cusp, and i feel more comfortable knowing the precats are gone. There are numerous people on here who have removed their precats without issue and that speaks volumes to me.
This is my reply to the points Mike raised, and I have been restrained in my response. Believe me I feel more strongly about this than my words suggest, but I am trying to be polite.
The last people I would trust are service personnel. Over the years and in my experience of driving and owning cars over 32 years, there are very few of them who I would trust any further than I could throw them!
I have read a great many posts on here that report engine failures due to precats, and I do believe they did redesign them , or at least their sleeving design.
I'm sure that the majority of our members trust the considerable depth of knowledge that is possessed by the more informed members. I don't consider that I have been misled on the precat issue or anything else in my time on here, and I certainly don't think the advice has been irresponsible. Theories etc posted up on here have been scrutinised and evidence and engineering logic always applied.
I for one , have no problem with the advice given to me by the more learned members here, and am extremely grateful ,as their wisdom has saved me bucket loads of cash and made the ownership experience more complete.
If an individual doesn't wish to remove their precats, that's fair enough as its personal choice. But taking out an item that isn't needed anyway ,and has a well documented history of failure , cannot do any harm.
If an individual doesn't trust the general advice on here , then , as Mark has said, there really is little point being a member really!
My post-'03 broke up twice as Mark has said. Leave them in at your peril regardless of year, just please don't come crying here in surprise when your engine goes pop.
just my 2 pence worth ....
Removing the precats takes a relatively small amount of time, needn't cost anything and has no detrimental side effects.
Whether you believe there's a problem or not it does no harm to remove them. And if you really don't want to do it, don't do it. Simple as that. I for one will be removing mine as soon as possible.
It's not really worth having a bit argument over is it?
From an older and wiser citizen!
If the NHS were to boast a 99% quality control success rate, then something like 100 wrong babies would be given to a mother every day!
Che is cheap, solves the problem, weighs less, looks better, passes the mot, and some may argue gives a bit more performance.
If you are just playing the percentages then the chances are you'll get away with it. The cats on my old manifold (30,000) were still intact
i want ours out of our 2 cars asap cant wait to get to the preecat removal meet.
Interesting comments, s:shock: :shock: s:shock: s:shock: :shock: s:shock: but it's all down to the individuals peace of mind.
I didn't remove my pre-cats I removed the whole manifold for a Che - the cars was 12months old and done 3000 miles, Toyota had no problems with me doing this and as long as it was serviced regularly they didn't give a s**t
I did this on the basis of a "potential risk" I value my car to much to even consider the risk, the advice on this site is first class - even the Yanks come on here for a bit of sense for god sake. s:wink: :wink: s:wink:
I'm now on my second generation manifold, de-catted and sports back box, I've also replaced the ECU, the car is great and does what I want - it still goes to Toyota for servicing and they love it, I can't keep the engineers out of it s:roll: :roll: s:roll:
So if you want to risk knackering your pride and joy - go ahead it's your decision.
Rob
From the other thread:
Quote from: "mikevernon@talktalk.net"I've now spoken to service managers at 3 reasonably large Toyota dealerships, none of whom have had to replace an engine damaged by failure of a catalytic converter.
That's quite normal, Toyota likes to keep their reputation as a reliable brand and they never seem to admit any issues are common.
I remember when my engine blew, I was also told that it was the first ever. They even claimed they contacted Toyota Europe and there hasn't been a similar case in whole Europe. And they didn't admit anything else, not even after I provided them with facts from here and on that german forum that it's more or less common issue. Heck, even that same dealership had already fixed two blown engines, which I found out later.
Of course it's totally up to you if you wish to believe what Toyota wants you to believe or the real life experiences from many owners. s:? :? s:?
When my engine went, it was on about 32,000 miles. Quote from the mechanic was the left bank precat wasn't where it was supposed to be! I.e it had fallen compleatly out of the manifold.
Now it may be that the bore was oval, or the piston rings leaked which destroyed the precat, or the precat fell appart and damaged the engine but either way they were causing the problem.
After the replacement short block and manifold, a quick visit to Marks left me with no more precats, safely thrown away in the trash can.
The right one was already starting to crumble, from the bottom...
Simon
Wuhey, loads of views on here s:) :) s:)
So if I go down the Che route would everyone suggest keeping the mr T gasket ?
Cheers
Its about £24 to buy all the new gaskets you ned from mr t, dont use the che supplied gasket, and for the sake of £24 it isnt worth re using old gaskets really.
Cool yea, for £24 I may aswell! (No one has part numbers to hand do they. I'll find if not :))
No emission problems or anything with the Che then I take it?
Quote from: "sponger_007"Cool yea, for £24 I may aswell! (No one has part numbers to hand do they. I'll find if not :))
No emission problems or anything with the Che then I take it?
No problems - the only time you will have an issue with emissions is if you remove your main cat.
Rob
Nothing to worry about with emissions mate.
It will give you a bit throatier exhaust tone into the bargain.
Che is currently running aGB on SpyderChat - well there used to be a place called SpyderChat s:lol: :lol: s:lol:
I'm in on the order myself, and i'm sure he'll be happy to ship to you too - he's even bunging in the Mr T oem gaskets this time, so don't worry about the gasket.
I would suggest you PM Che about it.
Lovelly job, I'll do just that.
Cheers for all the info & help s8) 8) s8)
My thinking on the precat issue is that while failure is relatively rare and seems to affect the older cars, it is still not a fully resolved failure. I wonder how many have taken the precats out and suffered gross engine failure?
My take on it is that if the cylinder bores or piston rings go and subsequently take out the precats, the catastrophic engine failure does not begin until the precats go. When they clog the main cat, you have the effects of running with excessive back pressure and the effects of the precat material being sucked into the engine.
It may be that without precats the engine would slowly develop loss of power, increased oil consumption ang generally show all the signs of a tired engine. With the precats in, the engine is usually quickly reduced to scrap.
Chris
PS my precats are still in the manifold, which is on a shelf in the garage.
Quote from: "roger"Gutted mine when one year old...first MOT this Saturday!!
and passed emissions with flying colours s:D :D s:D
if you do consider taking the cats out, as well as looking into the che manifold- take a look at this bumped thread s:) :) s:)
m http://www.mr2roc.org/phpBB2/viewtopic.php?t=12576 (http://www.mr2roc.org/phpBB2/viewtopic.php?t=12576) m
Quote from: "ChrisGB"My thinking on the precat issue is that while failure is relatively rare and seems to affect the older cars, it is still not a fully resolved failure. I wonder how many have taken the precats out and suffered gross engine failure?
i agree its still rare, places like this just seem to highlight the few cases we do have and we have still had a few 03+ ones go, however it is much rarer again, As for when the precats are removed, well who knows without proof, i have seen a few cases on here where the bores have gone oval and others where the oil control rings have gone
Quote from: "ChrisGB"My take on it is that if the cylinder bores or piston rings go and subsequently take out the precats, the catastrophic engine failure does not begin until the precats go. When they clog the main cat, you have the effects of running with excessive back pressure and the effects of the precat material being sucked into the engine.
It may be that without precats the engine would slowly develop loss of power, increased oil consumption ang generally show all the signs of a tired engine. With the precats in, the engine is usually quickly reduced to scrap.
i agree, the rings go and the oily fumes seem to dissintegrate the fibreglass/cat causeing them to fall on the main cat and causeing massive back pressure.
as for it happening to a tired engine, we've had them at 7k as well as 70k, so who knows why it starts
Quote from: "kanujunkie"Quote from: "ChrisGB"It may be that without precats the engine would slowly develop loss of power, increased oil consumption ang generally show all the signs of a tired engine. With the precats in, the engine is usually quickly reduced to scrap.
i agree, the rings go and the oily fumes seem to dissintegrate the fibreglass/cat causeing them to fall on the main cat and causeing massive back pressure.
as for it happening to a tired engine, we've had them at 7k as well as 70k, so who knows why it starts
Hi Stu
I am thinking that as the problem develops with precats in, the situation goes horribly wrong very quickly once the precat material has come into contact with the bores. However, with the precats removed, if you start burning a little oil, the problem may just slowly develop and the engine will become tired, losing its power over a few thousand miles the same as any other that is on it's way out.
As for a 7K engine failure, that could be any of a number of problems with manufacture or an oil level fall that was not observed, the disintegration of the precat before oil got to it, oil overfill pushing the stuff through the breathing circuit and subsequently through the engine and thus onto the precats, overfuelling causing precats to overheat and likely a few more I cant think of just now. On balance I still say better out than in.
Chris
I gutted the cats on my 2000 MR2 a month ago, and they appeared to be in good condition - at least they were until Mr Hammer and Screwdriver got to work!
Finding the cats in good condition was a relief, at least the damage hadn`t been done. New gaskets and a couple of hours saw the job done, AND it passed its MOT (at the local Toyota stealership) yesterday without a problem or a comment. I had wondered if they might have got used to (precatted) MR2`s passing emissions even when not warmed up, and wondered why this one didn`t.
Well worth it for some peace of mind - and it seems to perform slightly better - but that might be imagination.
Does anyone know why TTE decided to use a metallic pre-cat instead of ceramic pre-cat on the TTE turbo? Might it have been a cost issue? Heat issue? Or that they knew about the ceramic ones causing problems? Just a thought!
it's because the Ceramic ones "aren't the highest quality"
lets just say I beleive teh source s:wink: :wink: s:wink:
As an aside (and apologies as I am sure it is burried somewhere in the archives), does removing the precats in theory liberate the extra 2bhp the Celica has? or does the Celica use a different map / or another reason why it has a tad more power than the 2?
Whichever theory you support re cause / effect, I see removing the pre-cats as a no brainer.
Quote from: "sandstrain"Che is cheap, and some may argue gives a bit more performance.
I should say so, remember it's a direct copy of the TRD manifold (£870) - I gained 6bhp when I switched from gutted manifold to Che's.
(£20 per horse for what it's worth)
BTW - I didn't see any major gains after gutting my precats. Sounded a bit throatier though.
Although you say if it ain't broke don't fix it, I think from my own experience that there is an inherent oil burning issue with these engines.
IMHO the oil burning damaged the pre-cats which got back into my engine and exacerbated the oil burning problems... a vicious circle... now I seem to use more oil than the Arabs have to sell s:!: :!: s:!:
Therefore IMHO you should remove the precats before the engine destroys one/both of them and you enter the vicious circle... In my case I was too late to find out about the issue. You know about it now - think how sick you'll be IF you leave them in and IF they break up and knacker your engine.
Nothing in life is certain but you can take action now to reduce the probability of it happening to you...