[scoobaru03]

Till you replace or clean the IACV the CEL will most likely stay on. It shouldnt cause any other issues other than a rough idle. All that control valve is doing is measuring the air going past the throttle plate into the intake manifold. It makes sure your idle rpm is ok for the load on the engine. Heres a exploded view of the part its right on top of the Throttle Body. Oh yea be sure to get a gasket if and when you do replace it.

 

[scoobaru03]

Step 1. Disconnect (-) Battery Cable
Step 2. Disconnect connector from IAC valve
Step 3. Remove IAC valve from throttle body
Step 4. Remove gasket from throttle body

Install in reverse order. The 2 bolts you take off get torqued to 2.1ft. lbs. Make sure engine is cold too there is coolant running underneath of the IAC valve. And yes its right on top of the throttle body very easy access.

By dummies for dummies