Precat removal - How I did it...

[Liz]

My Mr T service manager called me today about more new wheels for the car, I told him to have a look at these threads regarding the pre-cat failure as he said he had no knowledge...are you reading this Andy!!?

[Tem]

I told him to have a look at these threads regarding the pre-cat failure as he said he had no knowledge...

Sounds just like Toyota...a while ago I told my friend to take his car in, cause the other precat was cracked. He took it to the same dealer who handled my blown engine and they just kept saying they nor Toyota have never heard of this problem before...

Later on we heard about 3rd case that had been there before me

I bet all Toyota employees have Alzheimers, cause they wouldn't lie to a customer, would they?

[GSB]

Addendum:


Regarding the manifold to main cat gaskets. They are indeed a use once design. The new gaskets measure 5mm thick, and once installed are crushed down to 4mm.

As a safety measure against future seizure of the studs, I coated them in Kluberpaste HEL 46-450, a dry screw lubricant and anti-sieze compound thats good for 1000 deg C. It's made by Kluber Lubrication, but I'm not sure if its generally available to the public, so if theres ever a "de-cat" meeting I'll bring some along with me.

[John Woodward]

Now, a "de-cat" meeting sounds VERY good. I like that idea...........

[Tomr2]

me too! hope it happens...

[da monkey]

the monkey is now (pre) catless, MAF sensor cleaned and ECU reset - the 2 is now a different car
just to say thanks for the write up and hey if a monkey can do it anyone can

so what do you find different?

louder exhaust but think i need to get a new main to cat gasket as per GBH hee hee i mean GSB
but def better low down torque/acceleration - could be removal of restrictive precats?? but probably cleaning of MAF but either way i is a happy monkey as car goes better and have no worries re engine failure due to precat degrade

[pp]

the monkey is now (pre) catless, MAF sensor cleaned and ECU reset - the 2 is now a different car
just to say thanks for the write up and hey if a monkey can do it anyone can

but def better low down torque/acceleration - could be removal of restrictive precats?? but probably cleaning of MAF but either way i is a happy monkey as car goes better and have no worries re engine failure due to precat degrade

I think you have more torque everywhere (I have). I have a 6 speed gearbox (2003 model), and before , it was just an overdrive. Now it is a real gear.
I noticed also an improvement in max. speed on 6 gear.

[Tomr2]

would be interesting to see a before and after dyno results...

the sooner we have this de-cat meet, the better!

[street_carp]

Also going back in the thread a little bit, has anybody else noticed the shape of the surface of the precat on the engine side? I am sure it looked dished slightly in the centre under the ends of the O2 sensors.If it has worn or broken up in that fashion its incredibly even,both sides identical, and if this is failure, I might as well throw my engine in the bin!

Mine are destroyed now, but I don't remember the engine sides being dished at all. They appeared flat like the bottom end. But this is for a US spec, and I've noticed in the photos here that the exit end of the precats seems to be closer to the bottom of the header, so maybe we have different precats altogether.

[GSB]

I'm sure that manifold i had looked like the pre cats were slightly dished, by this i mean the centre looked higher than the sides, convex rather than concave.(i think)

If you have mine yet, take a look at it and see can you?

I just took a look inside, and they look pretty flat to me. remarkably good condition too, how long were they on your car?

[mr-s_turbo]

Didn't pay that much attention, just thought they looked dished from memory.

They were on the car for about 7k miles. That was enough for me to dump it and go turbo.

[Eifel-Roadster]

Can you smuggle a tape recorder in with you and get that on tape please

Can you understand German ?

Kein problem immer her damit....

[Peter Laborne]

it was the same receptionist that told me about the MR2 TTE Turbo about 1 month before you had a mention of it on this site!

DRIFT

Victor

If you remember, I first found out (officially) that TTE were developing a turbo for the Roadster back in July 2002. Though at the time they hadn't finished building the first one

[loadswine]

Tried to gut my precats today and mega problem with one of the 14mm nuts at junction of manifold to main cat pipe.It totally will not budge,used penetrating fluid in abundance and good quality socket set,but nut is now burred and I'm completely snookered. Looks like I'll have to reassemble it and drive with my fingers crossed all the time. I hate working on exhausts!!!

[GSB]

If you go to an exhaust centre, they will extract it for you for a small fee, and you can then temporarily replace it with an M10 bolt for the journey to the Toyota dealer where you can get a new stud and nut, then back home for cat gutting and tea...

[Comer]

If you go to an exhaust centre, they will extract it for you for a small fee, and you can then temporarily replace it with an M10 bolt for the journey to the Toyota dealer where you can get a new stud and nut, then back home for cat gutting and tea...

Will Kwik Fit do this sort of bolt extraction then? I couldn't find my 12mm socket and I've rounded off one fof the 4 manifold heatshield bolts using a crappy ring spanner There other 3 are fine but no amount of WD40 will help me now.

[markiii]

assuming the mole grips wont.

can try it later today if you want?

[Comer]

Mark I'll pop round in about an hour?

[GSB]

Is it out? If not you might try a nut splitter? very handy for rounded nuts...

[Comer]

It's out now after Mark's hard work, thanks again Mark. He tried with various tools before we decided to cut the head of the bolt off with a Dremel and replace the heatshield (once sprayed) with only 3 bolts. But for some reason after Mark was halfway through the bolt head with the Dremel, I suggested trying the socket again and it worked!!!

I've kept the bolt as I can't believe it came out in one very battered piece.

[nitroxdiving]

Using a 22mm O2 sensor socket



Where can I buy one of these?

[GSB]

http://www.mr2roc.org/forum/viewtopic.php?t=2045

[nitroxdiving]

just ordered my 22mm sloted socket, cost £11.05 with shipping.

Thanks for the help.

[Slacey]

<MOD> Conversation regarding Jon's engine moved to here...... </MOD>

[Tem]

I had a bit of an issue with the manifold-cat bolts. They all opened pretty nicely (no wonder really, since they had only been on for ~500 miles), but two of them opened as "a bolt", while the nut opened in the 3rd one and the "bolt" was left in the manifold.

Should I be worried about that, or does it make any difference at all?

[GSB]

Makes no difference Tem, they just open what ever thread has least resistance.

[dieamond]

Just to be sure :
can somebody confirms that removing them doesn't make the car run louder ?

I currently have a TRD header, and with my Remus exhaust, the sound is too high for my wife

I'm thinking of putting back my stock header but I really fear pre cat failure (especially with track use), and would prefer to gut them.

GSB said there was no increase, but da monkey said the opposite.

I would like to know, as I can't cancel this once done.

Thank you.

[GSB]

On my car its probabley slightly louder now. Hard to say really, but its certainly changed the sound, its far more raw than it used to be, with pops and crackles now and then. Different... but I've had no complaints from my lady.

Of course if you want a good home for that TRD header...

[Liz]

Running mine with the A'PEXi and the H & S, mine is alot louder, so much so that people that know the car have commented on it and asked what I have had done.

[Slacey]

Mine is slightly louder, but not outrageously so.