Hoping someone can give me an ans. I am a owner of a 2008 cts4 and have a problem finding the ans. I step on the accelerator and sometimes it will bog down got code p0113 replaced mass sensor still does it but now if car does not bog down I 'll get a rattle in *** end as I accelerate so release gas pedal and sound gets worse. like a major shake in either exhaust or drive train any help would be appre.

 

If battery was disconnected you need to go through a throttle re-set. See owners manual