02 S6 Avant - 4.2: Odd throttle/acceleration issue
 

I have a 2002 S6 with 4.2.

Sometimes when leaving stoplights, the car accelerates rather slowly and it seems as if I have to push throttle a little bit more. Majority of the time, the car accelerates very quickly with light throttle for a big car, has excellent response.

I've also noticed that when accelerating at WOT, after the car shifts to 3rd, I can physically feel the gas pedal depress another 1".

Anyone have any insight into this issue with the 4.2? Thinking this is some type of throttle potentiometer/TPS problem?!