Yes -- clear the codes and see what comes back --

The oil pressure light would be my BIG concern because it indicates a bigger problem than a few CEL codes.

 

Re; oil light. As I had mentioned, the OP light goes OFF when you are at lower speeds and rpms. LIke it is wired backwards or shorted.

 

Sounds to me like oil starvation. The oil pump pumps the oil out of the pan faster than the oil can return. I've heard about in on some Olds big blocks, but not Audi's. How full is your oil? Do you know how accurate your dip stick is?

 

Carbon from cheap oil may plug up the oil intake before the oil pump. Also, the oil filter and the pressure relief valve may be plugged up. Which 2.8L 12 valve engine do you have?