Pre-cats: The Official MR2-ROC Information Thread

Started by Anonymous, May 16, 2006, 16:01

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Carolyn

#275
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.
Perry Byrnes Memorial Award 2016, 2018.  Love this club. 
https://www.mr2roc.org/forum/index.php?topic=63866.0

Ben

#276
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.

shnazzle

#277
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.
...neutiquam erro.

spit

#278
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
1999 MR-S with added C2 POWΣR

Humbled recipient of the Perry Byrnes memorial trophy (2007 & 2011)

SteveJ

#279
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 m

Bossworld

#280
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:?

DanThrax

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!

Carolyn

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.
Perry Byrnes Memorial Award 2016, 2018.  Love this club. 
https://www.mr2roc.org/forum/index.php?topic=63866.0

DanThrax

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.

Chase27

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.

Call the midlife!

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??


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Chase27

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...

Call the midlife!

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!


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Hamezi

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.

AdamR28

Should be fine as long as you keep the standard cat and everything else in good order.

1979scotte

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
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