I own a 2001 Audi s4 2.7 bi-turbo. The situation is usually always the same. Shifting from 3rd to 4th is smooth around 4200 RPM. Once I hit 4000 RPM in 4th gear, it seems the turbos and RPM want to pick up but remain stuck. The engine sort of bucks a little. I don't know if the waste-gates are sticking or possibly if the VSS is producing faulty information to the ECM. Although, it only happens when the engine has reached operating temp. Sort of frustrating when you're trying to get on it. Well any suggestions would be greatly appreciated.

 

Does any lights flash on the dash board when this happens? Like the Battery light?

 

The Battery light doesn't flash. Every once in a while the ESP light will come on and stay on. It's suppose to blink but it's solid. When I open it up I just have an intense lack of power.