idling problem

please help.. i have a 95 mustang v-6 3.8 .. had a new clutch put in by a shady mechanic.. cost me a ton.. so i had a new clutch put in AGAIN... much better.. only issue is the idle.. it starts right up.. goes through its rev up cycle and then tries to idle down... but when it does it goes to about 1100-1200... i myself know its not good..and also when you shift gears it revs up by itself to about 1700.. stays there for a few seconds and then slowly creeps down to the 1100-1200 range and stays there.. sometimes it likes to go up to 1500 and stay there and idle for as long as you let it.. any ideas would be apreciated.. the car had a complete tune up last week.. all motorcraft parts.. to include a k&n air filter. the car was running fine and normal before the clutch was installed.. this high idle drives me NUTS.... thanks for your time..-Brett

Sounds like the IAC. But it could be the TPS.