i have a 2000 a6 2.7t. i have been noticeing that my car has been getting worst gas milage and has been feeling weaker and slower.. my car feels like it doesnt have as much power as it should. so i brought it to autozone and they came up with 4 codes... 1. p0421...2. p1131..3.p1411..4.p1423.. now the descriptions for these codes are very vague and dont tell me much. two of them they didnt even have descriptions for.. i would really love to restore the power and gas milage back to my baby, she just dont feel the same anymore.. someone anyone that can help or point me in the right directions would be amazing.. thanks jon

 

I am not good with codes off the top of my head, can you add the code descriptions in? The first thing I would check on a 2.7L biturbo with CEL and loss of power is the rubber "Y" pipe in front of the throttle valve that combines the two boost pipes and they tend to tear on the underside creating a boost like which will cause fuel trim faults and well as boost faults.

 

creating a boost "leak" not "like"... sorry