I had some shifting issues for a couple of months now,it would hesitate going from drive to reverse then back to drive,it would take a second or two to fully engage,if i was in a hurry and pressed the gas to hard while shifting gears it would feel like a thump noise coming from the trans or the RDU,after cleaning the throttle body and intake a few days ago and found it full of carbon,it remedied my symptoms and its shifting better than ever,hope this helps someone . Z