Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[geoff]

on your mot every thing pass apart from fast idle co2 test what could be the problem any help or advice would be much help thanks :yand cat was changed a year ago but used old lambda sensor

[geoff]

does anybody now what is wrong i'm thinking of changing cat and sensor any idea's?

[magnul]

I guess you mean CO emmisions?
If HC was low, but CO high, it usually means that the cat is fully functional, but the car is overfuelling (cats can partially oxidise the HC to CO, but not enough oxygen to fully oxidise).

If you have a decent DMM, you can check the operation of your lamda. It can get fairly tired before a fault code shows up. With lambda still connected, connect to the black lambda wire (with a sharp probe or connector that penetrate the isolation). Measure the voltage between black wire and ground at idle. It should fluctuate at ~1Hz frequency between ~0.1 and 4.7V. If it fluctuates slower or not to the extremes in signal it is likely that the lambda is tired.

[geoff]

co limit was 0.30 car read 0.58 on first run and 0.60 on second,going to try lambda sensor of another car i have witch is for spares