Pre-cats: The Official MR2-ROC Information Thread

[Rafsmr2]

I recently had my precats removed by Luke at Pacific Works in Luton, a really nice guy and he did a great job

[Anonymous]

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 .. ??

[shep1975]

Anyone know of a garage that will de cat the pre cat in South Wales? Thanks guys

[eynonz]

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 m

[Anonymous]

Would you expect the pre-cats to have failed by now on a 2000(X) 80K MR2?

[AndyM]

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.

[Funk]

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.

[philipouk]

Anyone know of a garage in Devon/Cornwall that will de cat the pre cat? I'm based in Exeter.

[Anonymous]

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

[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.

[Anonymous]

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.

[Wabbitkilla]

Did they make sire the car was warned up before testing?

[Anonymous]

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

[Joesson]

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.

[Wabbitkilla]

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.

[redcarblackhorse]

what about some fuel treatment - like Millers - my local garage says this has helped cars pass.

[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.

[Anonymous]

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

[Wabbitkilla]

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 l

[cptspaulding]

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.

[James and his MR2]

So with huge thanks to Loadswine my pre-cats have now been removed   s: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:  




Pre-cats out!   s:bounce: :bounce: s:bounce:    s:bowdown: :bowdown: s:bowdown:    s:bounce: :bounce: s:bounce:    s:bowdown: :bowdown: s:bowdown:  



Expensive rare materials for the dustbin  s:) s:)



Didnt realise how thick the pre-cats were   s:scared: :scared: s:scared:  



And finally my sprayed manifold that went back on  s:) s:)

[bobbybsings]

Is there any benefit to fitting a new manifold without the pre-cat chambers?

[Anonymous]

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.

[sailingsmith]

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

[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.