Having fitted a decat exhaust to my 00MY turbo the check engine light came on about 750 miles later, which was conveniently the day it was booked in for service. It was diagnosed as an oxygen sensor fault and was reset. This week (500 miles later) it comes on again, so I stop the car and restart, light gone. Today, less than 50 miles later it comes on again. In each instance it comes on, stays on 'til you stop and restart the engine. Is it the decat causing this or is it worth me spending £100ish for a new O2 sensor? Please advise as I'm thinking of removing the downpipe which I really don't want to do.

thanks

Glen

 

Glen,

a decat will cause the OBDII check of the catalyst to fail (since it isn't there). It's probably not the sensor, and an "O2 fix" or a remap will cure the problem.

Cheers,

Pat.

 

Pat, you have new age's on the brain - I wonder why?

Glen - on a my00 there is no efficiency check. Your garage is at fault - resetting the ecu will get rid of the stored CEL, but unless they fitted a new sensor you've still got the problem. I guess your car smells like a petrol factory at idle? New lambda sensor required.

Richard

 

Pat/Rich
thanks for your input, it seems OK at idle and isn't using loads more fuel, p'raps it's on the verge of failing?

glen

 

No - if you're getting a CEL it's pretty bad already. I could sniff mine before I got a cel (as well as see it with logging software). Assuming the cel is lambda, of course

Richard

 

Richard,
did your idle go lumpy as well as the fuel smell?

glen

 

Nope - lumpy idle suggests either Lambda or MAF (could even be the idle valve), hence my reference to the CEL. You really need to know which error code is showing. Regardless though - something needs replacing, not resetting

Richard

 

Richard
is the o2 sensor and the lambda not the same thing? When I first had the light come on (less than 1000 miles ago) the dealer said it was the o2 sensor code, I am assuming it it the same code again?
I don't have alumpy idle, just thought it was one of the symptoms of the o2 sensor.
glen

[Edited by glen4 - 1/24/2003 10:35:19 PM]

 

Lambda and 02 are the same thing

Watch the advice you give....

MB

 

Richard,

ah, yes, I need to read the post don't I? Then I would have spotted it was an MY00 not an MY01 Ooops. Best thing to do is to read the error code out of the ECU, and then decide what needs doing....

Cheers,

Pat.