Topic

Hi
I have a '96 MGF 1,8i. It is running perfect, but i have a problem at MOT where it did'nt pass because the co was a little high (1,5) and the lambda a little low(0,96) assuming rich mixture.
AS Said the engine is running perfect and there are no deposits on the plugs. I have made a diagnostic with a PSCAN, and there was no FAULT codes. The live data also looks very fine, but 3 numbers may be problematic:
The mixture is 14,5:1 . Is this to high and is it possible to adjunkt
The air intakte temp is 59 deg. Is this to High and if is is then why.
The stepper motor reads 16. Is this to low and does it matter

Sort my english (i am from Denmark)

hmm, could be:
- a dirty or faulty idle air control valve
- a faulty mass air flow sensor
...or something else. Surely more suggestions will follow.

and - welcome aboard!

Theres a tiny black plastic air pipe from the ECU side to the other side of the rear of the engine bay. It goes across the oil filler bracker area and gets a hole worn in it.... just check it as that can also cause high emmisions. A piece of tape over the hole if it has one will get you by until you change the pipe!

Thank you for the Quick reply's. I will check.

Just a little update:
I changed the catalytic converter to a new one and the car samlede thru MOT with almost zero emissions
(I have switched back to the old converter, so a have a new to the next MOT)

Glad to hear it passed.