Pre-Cats Decision..

[Anonymous]

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.

[markiii]

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]

[carl_evs]

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!!

[Wabbitkilla]

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.

[loadswine]

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!

[Anonymous]

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.

[Anonymous]

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?

[Anonymous]

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

[Anonymous]

i want ours out of our 2 cars asap cant wait to get to the preecat removal meet.

[Anonymous]

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

[Tem]

From the other thread:

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:?

[SimonC_Here]

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

[Anonymous]

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

[Anonymous]

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.

[Anonymous]

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?

[Anonymous]

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

[Wabbitkilla]

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.

[Anonymous]

Lovelly job, I'll do just that.

Cheers for all the info & help   s8) s8)

[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?

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.

[roger]

Gutted mine when one year old...first MOT this Saturday!!

and passed emissions with flying colours  s:D s:D

[freak_in_cage]

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 m

[kanujunkie]

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

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

[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

[Anonymous]

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.

[Anonymous]

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!