2002 Audi Other engine

Couple things I would try. If you don't have any miss fire codes carbon buildup could be your problem. Your starting to get a lot. Of miles on your car and biproducts of combustion are building up in you fuel system. Try buying a 3 part cleaner from the auto parts store. One part clean you intake valves the other additive cleans your injectors. Lastly clean your throttle body to make sure that the butterfly Valve is free to open and close all the way. You can also have this service performer for about 70$ of you don't feel comfortable. Doing it yourself. Things like conventional oil and regular gas could also be causing you car to run poorly. Let me know