Engine is idling or racing a little loud after sitting about five hours or more! on 2004 Audi A6 Quattro

In the morning the engine is idling or racing a little loud. When you take off the engine seems to be stalling until about 3min of driving. Then the car runs fine. This happens only when the car has been sitting for more then five hours at a time.

Asked by for the 2004 Audi A6 Quattro
Most likely you have a Check Engine light on Yes? Best to Check the codes and go from there. That way you will be tracing down the real problem and not guessing.
Engine light is not on!