It's located on the side of the intake plenum. Follow the large rubber hose to an aluminum casing, it's mounted there.
It has two solenoids (motors)that open and close a "butterfly" (flap) to control the Idle speed. With mileage and ingested dirt/deposits it becomes sticky. You usually can clean it with choke cleaner and it will run normally again. Be careful not to get cleaner on MAP/MAF sensor inside rubber hose.
The "bone" yard will cost you much less than at the dealer and they usually give a warranty on used parts.