check enginelight on 2006 Audi A4 Quattro

what does a code 422 mean with check engine light on?

Asked by for the 2006 Audi A4 Quattro
If you are talking about a P0422 trouble code (P0422 Main Catalyst Efficiency Below Threshold, Bank #1), then it refers to the efficiency of the catalytic converter. Here is some related info: