On my RS6, i've repeatedly had the CEL of rich, as well as lean, for both banks, come on. anyone have any suggestions where to start? thanks. car is stock, though it did have an APR chip for about 500 miles.

 

Rich and Lean? I'd be looking at that MAF sensor and try cleaning it. If thats ok your O2 sensors could be malfunctioning and oh man, not a fun job on an RS6 let me tell ya.

 

well thanks for the info. I took it into audi north scottsdale, turns out that the tech who was helping me troubleshoot a lack of power withthe APR chip, while swapping out my N75 and Thrustsensor didn't put everything together quite perfect, and it created a leak. So $200 later in labor (which i consider a steal btw at a dealership) and $0 in parts, the cel is gone (at least didn't come back on during drive home....)