hi you all!!

i have two fault codes in my car (audi a4 b5 1998 quattro V6 2.8): "16556 P0172 Fuel Trim, Bank1 System too Rich" and "16559 P0175 Fuel Trim, Bank2 System too Rich".

My mechanic told me that i have to change two oxygen sensors. I did it (bosch universal type) and the problem still. He insist i have to change the oxygen sensors for a OEM ones, any opinion or ideas to solve this problem??

I would try cleaning the mass air flow sensor. Parts stores have a special spray cleaner. Just be sure to let it dry COMPLETELY before you plug it back in.

Lou

The universal sensors work fine.