Car is a 2007 gli dsg. It has a rough idle and the idle gets worst when it is in park of neutral. Ive already had my intake valves cleaned, spark plugs changed, pcv valve replaced with latest revision, fuel filter changed. I brought the car to the dealer and they told me that they cant find anything wrong with the vehicle because there is no code even though they felt the rough idle.
Dont know what else to check
any help would be greatly appreciated