A 2001 Monte with the3.4.What controls the idle speed.It just started to not idle down when you let off the accelerator..Will drop to 1000 but wont drop any further other times its 1500.Then sometimes it will run normal.Any help would be appreciated. Scott

try your mass air flow sensor.

it's the iac valve, mounted on the side of the throttle body.

it's the iac valve, mounted on the side of the throttle body.
Will this throw a check engine light if this isnt working?