This is most likely an indication of a vacuum leak(see 4th paragraph) I would do all these steps though.
the IAC is on the back of the intake, between the intake and firewall. has a 2 pin connector and 2 coolant hoses attached. remove and clean with brake or carb cleaner.
Clean the idle control screw and it's passage. Take care to note the # of turns it's at by screwing it in until it softly bottoms out, then removing it. When it's bottomed out use a pick to clean the factory sealant off.
Also check the fast idle valve on the bottom of the throttle body. with the engine fully warmed up, remove the intake duct going to the T/B and plug the lower port with your finger. It should have no vacuum ideally, but it might leak a little. when blocked off it should not affect the idle. if it drops, you can try cleaning it too, but likely this will need to be replaced.
All this is done easier, if you remove the T/B assy first, then the IAC. those hoses are a pain sometimes. then you can clean the T/B too to get rid of that sticky pedal.