if your idle is off or you have a whining noise this may be all you need to do instead of buying a new IAC valve try cleaning it.
remove the IAC valve from the intake manifold by removing the 2 10mm bolts, and disconecting the plug
remove the black cap on the side of the valve to allow it to drain and dry properly, this is just a vent cap
you can use sensor cleaner or electrical cleaner. spray in the 2 holes on the side let it drain and spray some more, there is usually alot of carbon build up in there it may take several sprays
let it dry compleatly before re-installing