Pre cats dont fail?

[yorkie1865]

Visited Mr T for some rather exotic power steering fluid £32 thanks  s:shock: :shock: s:shock:   and queried new power steering pipework £332 not fitted.   s:shock: :shock: s:shock:  And whilst on the subject of the car he told me to use only 5w 30 oil of the highest caliber for it too. as they do like their oil. I said mmm and they like precats too dont they? and apparently not." unheard of I worked here for 15 years blah blah blah..... never an issue".Funny I said the forums are alive with ceramic precat removal and issues.  s:shock: :shock: s:shock:  "Dont believe all you read sir." ok thanks.  s:? :? s:?  so there you have it precats dont break down and there isnt a problem  s:D s:D

[Joesson]

Well that is reassuring.
However, I have removed mine as I read several very dodgy reports supported by equally dodgy photograhs!

[mrzwei]

At the risk of fuelling another pre- cat debate, almost a founding cornerstone of the forum, there is very little first hand evidence of pre- cat failure on the forum, albeit there is some. The vast majority of members who have removed them have reported that they were intact.
The fundamental issue with the 1ZZ engine is sludged up oil control rings which cause excessive oil consumption and big end failure if it is not addressed or managed.
It would seem that it is excessive oil consumption that causes the pre-cats to fail.
In that respect your Toyota dealer is right, they won't have seen much evidence of pre-cat failure. What Toyota did put their hand up to was the oil control ring failure and replaced short engines accordingly.
Given the age of the engines now then it is likely that oil consumption will cause more pre-cats to fail but the engines are more likely stuffed before they do.
Some of the excellent early reading material in the reference section should possibly be updated because it creates a wrong impression that if the pre-cats are removed then everything is ok.
Personally, I'd still remove them but then I still won't walk under a ladder   s:lol: :lol: s:lol:   the greater priority is to keep an eye on the oil consumption.

[Wabbitkilla]

Obviously I believe a local Toyota garage over communities from around the world....

Removed from a car last week;

[carolineasb]

I think MrT will say that because any cars they have likely seen are when people first complain about the oil useage which is a symptom of the problem with the OCRs just as the pre-cat failure, it appears, is also a symptom.  Most cars (with the caveat not all of course) that main dealers will have seen will have been while they are pretty young and so any oil consumption problem may have been cured by a new engine under warranty (most likely the 7 year one that MrT suddenly introduced) and so they may have never got to the stage of pre-cat breakdown perhaps of a slightly older car.  

I would have thought that if MrT thought the pre-cats were a problem they would have changed the pre-cats in some way instead of updating the OCRs twice in the life of the Mk3?

[Davegtst]

I bought an mr2 a while ago.  One pre cat was completely broken up and the other was just starting to go.  The engine turned out to be knackered because of this.

[Anonymous]

Unburned contaminants (oil) passing into the exhaust knackers pre-cats....... Not engines CLICKY

Unburned fuel or contaminants entering the converter, can cause the heat to rise out of control. These contaminants enter through the exhaust. Excessive heat can melt the honeycomb support.

[Joesson]

Chicken egg or egg chicken!
I favour the OCR wear resulting in excessive oil consumption prior to precat failure but whatever way round the result is the same.
As for Mr T he told me that I would need his expertise to reset the ECU/EMS (which is it?) after I declined his offer  to replace a sensor in favour of doing it myself!

[Joesson]

The link that Les provided makes general sense to me.However the comment about the odour of rotten eggs indicating a contaminated catalyser is debatable.
From 1973 to 2010 I had a new car every 2/3 years. The early cars with catalysers gave off a distinct rotten egg odour from new so I am unconvnced on that point.
But maybe it supports my  chicken/egg, egg/chicken  comment!!!

[Mike G]

Obviously I believe a local Toyota garage over communities from around the world....

Removed from a car last week;

Intresting .........  clearly breaking down but not much evidence of being oil contaminated    s:? :? s:?

[Anonymous]

You wouldn't see any oil, as the cat runs at a very high temperature it will burn it off as with any contaminants.

[Mike G]

You wouldn't see any oil, as the cat runs at a very high temperature it will burn it off as with any contaminants.

Its just that I was reading a thread a day or two ago about a guy on here that had just bought a 2 from a dealer that was a burner (he would'nt take much advice........  but thats another story)
His photo of his collapsed precats were seriously back and carboned up , nothing like as clean as these ones pictured

[mulaz]

Removed my precats today from my 54k 2004 roadster even though
they were all 100% solid.
Better to be safe than sorry
you never know what they would be like next month?

10530682_10152596792414491_4544427671694995024_n by jarrow mulaz, on Flickr

10537398_10152596792459491_6806280420457266802_n by jarrow mulaz, on Flickr

[Joesson]

You wouldn't see any oil, as the cat runs at a very high temperature it will burn it off as with any contaminants.

Its just that I was reading a thread a day or two ago about a guy on here that had just bought a 2 from a dealer that was a burner (he would'nt take much advice........  but thats another story)
His photo of his collapsed precats were seriously back and carboned up , nothing like as clean as these ones pictured

I suggest that the difference between the two cars and two photos is TIME.
I can' t think of any man made item that when damaged does not get worse with time.