kid unknown

hi Just failed MOT on Emissions, the car is 93 wrx import which still has standard exhaust apart from scoobyworld ninja backbox. here are the test readings.

Fast Idle Test :

fast idle Co vol% 6.34 Failed
F. Idle HC Volppm: 313 failed
Lambda : 0.839 failed

2. Fast Idle Test :

Fast idle co % 0.66 failed
Fast idle HC ppm: 223 failed
Fast idle Lambda 0.983 Passed

Natural Idle Test :

Idle co vol%: 0.44 Passed.


any idea's what the problem could be?

thanks

LeighJ

Mine recenlty failled an MOT due to emmissions, turned out to be a leaking turbo gasket.

FiveO

Your Lambda sensor looks like its shot. Choices are get one from Subaru @£280 last time I checked.
Or get a three wire sensor (red, white and black wires) for a UK turbo and join them. The wires are titanium so you can't solder them. Crimp connectors and heat shrink sleaving works well.
Or get a second hand one from the breakers in exchange and mart.
Or I think lucas do a universal one. If you do a search you should find the part number SEB 230 rings a bell but I'm not sure.
You will also have to remove the surrounding heat shield to get at it, which is not as hard as it looks.