car problem advice needed

i work at a porsche dealer and i know the V8 coilpacks for the cayenne like to crack and cause the same problems you describe but i know nothing about dodge or anything american for that matter but perhaps take it into consideration.
good luck

SOUNDS LIKE IAC. TRY CLEANING THROTTLE BODY FIRST, DONT USE CARB CLEANER USE THROTTLE BODY CLEANER ONLY, CARB CLEANERS USE CHLORINES THAT CAN DAMAGE FUEL INJECTORS.