Is there anyone in the south-east Michigan area or Toledo that can assist with diagnosing my 2005 A8. I will drive to you. My OBD reader says P0171 and P0174 (to lean banks 1 and 2). A UK forum said that I should test my lambdas sensor first because “lambdas are a bitch to get to on these” (UK FORUM). My fuel economy has recently started to dip. When I put gas in it, it gives me a range estimate in my instrument panel screen. This range decreases by increments of 5 miles every 1.2 (actual) miles or so. Also, forgot to mention, I don’t have esp or traction. Fuses are good. I know this is a shot in the dark, but thank you for any help!