EPC light with shaking & noise
 

Thanksgiving afternoon I was driving my 2009 A4 Quattro on the freeway when my EPC light came on. I noticed the car was idling rough and I lost most of the power, I shut the car off and the light went out, but later it returned with the same issues. I had my mechanic look at it and he believes it could be the turbo.I have spent many hours looking online regarding this issue and no one has said anything about their turbo. After a tune up I drove the car and now when it goes over 40mph I hear a lot banging under the car whether the EPC light is on or off. The C.E.L. is on as well. Does anyone have any suggestions before I take the car in.

Coil packs. There is a TSB on those.