S3 rough running

[jwood662]

Hi can anyone help please, about 3 weeks ago my check engine light came on whilst driving, causing it to lose power and judder at around 5000rpm I got it checked on vag com which said the no1 lambda probe was at fault. Changed it but problem persisted, got it back on vag com and changed two coilpack that supposidly were iffy but other than that no fault codes came up. Changed the plugs and water temp sensor at same time but still have the same issue!

However, it did run fine for a couple of days inbetween the two vagcom checks with no loss of power whatsoever but now is back to running rough and failing the emmisions test on its mot.

I suspect the cat has been damaged from the overfuelling. Does anyone have a similar problem?

Its a 2001 y reg s3 210bhp

cheers

Jez

[kite]

Unplug the airflow meter and see if it runs better.
Could be a failing MAF.

[jwood662]

Cheers will give it a go, surely this would have come up as a fault when we plugged the vagcom in though?

[kite]

Faulty MAF doesn't always give a fault code.