non lc - mr2 emissions problem

[Jimbo4x4]

Help me out here, I've just put the mr2 through its first mot in my ownership and it failed on sticky calipers and emissions. The calipers I can sort, but emissions is a foreign issue to me. I did an oil and filter change as it was almost due anyway and I've run almost quarter a tank through with a quadruple dose of redex in. This has brought the lambda and hc in line on the retest yesterday but the co level has gotten worse! I changed the exhaust for one designed for a 91 model earlier this year (mine's a 95) which cuts out the cat but the engines on both cars are the same so it shouldn't make any difference. I don't want to have to go to the expense of a complete new exhaust system :-S

Any ideas on how to get it through? Any help much appreciated.

Jim.

 

[grantw]

I'm guessing that 1/4 of a tank also involved an Italian tune up?

 

[Doodle]

I changed the exhaust for one designed for a 91 model earlier this year (mine's a 95) which cuts out the cat but the engines on both cars are the same so it shouldn't make any difference.

It does from an MoT perspective. Post August '92 models have much stricter requirements, and without the cat that it should have fitted it will be very difficult (if not impossible) to get the figures low enough for a pass.

To give you some idea:
Pre 92 - CO 3.5%, HC 1200ppm
Post 92 - CO 0.3%, HC 200ppm.

I don't want to have to go to the expense of a complete new exhaust system :-S

Any ideas on how to get it through? Any help much appreciated.

Jim.

Find a "sympathetic" MoT station, or change the exhaust.

 

[adrianr]

You could try adding acetone to the fuel.

I have an article if you want a read. I've been using it for years.

Good luck in any case.

 

[Jimbo4x4]

Jeez drew, that's some difference! I'm pumping out 60 ppm hc and .61% co, was .48% on the original test so it's doing pretty well considering! Think I'll have to have an ask around at local mot stations, 2nd hand exhausts with cats are pretty much non existent as they rot quickly meaning they can't be removed in one piece.

Adrian, if you have a link to that article it might make for useful reading, thanks.

Jim.

 

[Jimbo4x4]

Sorry grant just seen your post... It's been pretty wet recently so tricky to do a decent job of it in a rwd car, but it got a good 20 mins on the m53 at high revs

 

[Doodle]

I know this situation well...the SL has just failed with a CO reading of 2%. Pretty sure the cat is dead, a new OEM one from Mercedes is £1500.

 

[Jimbo4x4]

Just been speaking to an experienced (read - old) mot tester who tells me the cat can only be relied on to take out 0.5% of the co, which would bring me in okay but not so sure about your merc drew :-S

 

[Doodle]

It's a *very* large unit - probably about 4-5 times the size of the one on your MR2. On later models they switched to a 4 cat setup, twin downpipes with a pair in each.

 

[Shayne]

Is this what you need ? http://www.ebay.co.uk/itm/Toyota-MR...arts_Vehicles_CarParts_SM&hash=item58a809aaa1

 

[Gary820]

Tbh should've failed for having no cat fitted too! Cat back on should bring it in line.

 

[Dave_S]

Is this what you need ? http://www.ebay.co.uk/itm/Toyota-MR...arts_Vehicles_CarParts_SM&hash=item58a809aaa1

Nope - thats for a Mk3 - if its 1995 it'll be a Mk2 - completely different motors...

 

[Beau]

I always give my cruiser a blast down the motorway for a good hour to burn off any residual carbon in the exhaust, never once failed or come close to failing plus I have upped my fuelling...

 

[Doodle]

The diesel test is considerably less rigorous though - they generally have to be really quite bad before they fail.

 

[Tractionman]

I agree with Beau, - take it in good and hot. After my 70 series failed 2 years in a row, friend/owner of my local garage/mot place told me this, which is all he did when mine failed. I normally book 8am appt. so vehicle is pretty much below normal when taken in. Now after a gentle warm up, I blast it on local dual carraigeway and take it in - no probs !!

John

 

[adrianr]

Not ideal but pulling the air filter out
for the emissions part might also help?

 

[Jimbo4x4]

I've managed to get hold of an inline cat that will fit if I weld a new flange in where it's going

 

[Gary820]

When you fit make sure its not too far back in the system, a cat works more effectively when its hot.

 

[Jimbo4x4]

I have approx 18" between manifold and back box, but thanks for the tip

 

[Gary820]

Yeah kinda guessed would be a short system, bet there's not much space to work!!!