tommyaet

I have a 1995 impreza wrx import i recently tried to MOT the car but it failed on emmisions CO2 was 3% instead of 0.3% and Lamba was 0.93% instead of 0.97% at idle. Tried replacing Lamba sensor which did not work, did a service and added engine cleaner to the fuel also retested when hot, but still failed.

My WRX uses a z4 ecu the garage tried a substitue ecu and it seemed to work when they tested emissions but they couldn't understand why?

Has anyone had this problem before? It is costing me a fortune which i aint got would really appreciate any help or ideas from anybody.

Many thanks Tom

34srm

cat

tommyaet

dont think its that cause they tried another ecu and it passed the emission test. thanks for trying

myblackwrx

iTrader: (1)

May be a bit weird but what emissions test did they use as pre Sept 95 you can blag it as a non cat test

robsw

I will have to check but I thought it was pre March 95.

myblackwrx

iTrader: (1)

http://www.type-ra.co.uk/images/emissions.gif although this says July95

The rookie

iTrader: (1)

If the CO is 3% then its running far to rich for the cat to do anything (confirmed by the Rich Lambda), would sound like an O2 sensor fault (it can't sense 'Lambda' only Oxygen), but you say a new ECU fixed it...I can only assume your ECU has learnt a dodgy setting and maybe could do with a reset.

Simon

robsw

http://www.vosa.gov.uk/vosacorp/repo...01992-2002.pdf

Yep, looks like 31st of July 1995 or before is the non-cat test.