My low mileage (10k miles) has been acting up a bit lately. Idle can be a bit rough/shaky at times. Thinking it may just need a tune up. Last year I replaced ALL the fluids, put a new heater core in (leaking), and replaced ALL the filters. She is still ideling a bit rough. Thought it may have been some stale fuel but just put fresh in drove an hour and still doing it. Any suggestions? If I were to do a tuneup what would be a complete job for this truck? Should the fuel injection system be cleaned? Truck also will shift a bit hard when romping on it, not sure if that is normal for these trucks or not. I am not mechanical so I have a good shop to do the work.