Failed Mot Test Emissions On Celica St202

[pmunns2007]

Hi My Celica failed the MOT emissions test today with the following figures

FAST IDLE

CO <.30 MINE WAS 7.42

2ND FAST IDLE

CO <.30 MINE WAS 7.04

NATURAL IDLE

CO <.30 MINE WAS 5.53

these figures are way high, the guy in the garage suggested trying to change the ECU tempertaure sensor (located in the cooling system) does this make sense to you guys???

help please

thanks

paul

[tea sport]

Sometimes resetting the ecu will bring down the emissions on older Toyota's. To try this remove the EFI fuse and leave it out for a few minutes. Also a fuel cleaner and good hard drive to clean out the engine. I have got many older toyota's through tests this way. If that doesn't work possibly an oxygen sensor or cat.

[pmunns2007]

Sometimes resetting the ecu will bring down the emissions on older Toyota's. To try this remove the EFI fuse and leave it out for a few minutes. Also a fuel cleaner and good hard drive to clean out the engine. I have got many older toyota's through tests this way. If that doesn't work possibly an oxygen sensor or cat.

do you mean the Lamba sensor or the ECU temp sensor thats in the cooling system??

thanks Paul

[GT4 BOOSTER]

what were the lambda readings on the mot ???

[tea sport]

Sometimes resetting the ecu will bring down the emissions on older Toyota's. To try this remove the EFI fuse and leave it out for a few minutes. Also a fuel cleaner and good hard drive to clean out the engine. I have got many older toyota's through tests this way. If that doesn't work possibly an oxygen sensor or cat.

do you mean the Lamba sensor or the ECU temp sensor thats in the cooling system??

thanks Paul

Yes the lambda sensor. however it is only a guess.

As for the coolant temp sensor if it is faulty the ecu would incorectly fuel as it may think the engine is cold or go to safe values. But again just a guess.

[tea sport]

Try the thing with the efi fuse first.

[pmunns2007]

what were the lambda readings on the mot ???

the lambda values were

as follows

1st fast idle .806

2nd fast idle .811

thanks Paul

[GT4 BOOSTER]

http://www.bobmckay.co.uk/p_emissions.html

[BenMMellor]

hi - I've been in your situation.

Couple of things to try which are cheap.

1. check the exhaust system from the cat back for any holes - they let air into the exhaust gases and really %$( up readings. For example, check my post on TOC! about my 'swiss cheese' Blitz exhaust.

2. Get hold of some Forte injection cleaner - I've used this in a few cars which have failed the emissions tests and it's cured the problem.

Failing that you then look at changing the O2(or Lambda) sensor - these can be had for about £50 for a pattern part or £130 ish for a genuine toyota one. the pattern part needs you to alter the wiring.