okay so i have a 2009 Audi A4 quattro it runs so smooth! HOWEVER when i'm in idle while in park or at a stop light/sign while in drive my car starts to shake and i can almost hear like a little sputtering sound out my muffler.. but as soon as i start driving again it goes away and rides like an angel. if i allow it to idle for more than 5-6 minutes without moving it will shake really hard and the EPC light comes on. there are no other lights that come on . i currently have 109,100 miles on the car.

Ive already replaced the spark plugs and coil packs so thats not it.

can someone shed some light please.

 

It could be in the Crankcase ventilation system. Check for any cracks or splits in the system & if the One way valves in the system are working.
maybe clean the MAF sensor because if it is the CVSystem, they sometimes get dirty but since it runs smooth while not idling, i think it's clean.

Turbo? Any modifications?