Went to the MOT today with the cossie and CO reading was 8.6%. Car drives fine. Put the CO back towards the required 3.5% max. and passed the MOT. But the car felt than like it needed more fuel to drive smoothly so I turned the CO screw back.

Before the MOT I put a new TPS, CTS, ATS and map sensor in it. Renewed the oil and plugs (071's). Checked the timing, vacuum and fuel pressure. Done this all because of this high CO problem.

I cant figure out why it has to have a so high CO value at idle to drive smootly.


Its a 1991 4x4 non-cat, msd chip, greens etc.

Anybody got a hint for me what it could be?