It is probably the Idle Air Control Valve, IACV, which keeps the idle steady when cold or under engine load. It is located on the intake manifold near the throttle body. It may need to be replaced or you can check the ports that it opens and closes for carbon deposits to see if you can just clean out the manifold and throttle body ports.
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Sunday, December 23rd, 2012 AT 2:58 PM