"I observed a clicking sound coming from the firewall area. I turned the ignition from the ON position to OFF, then I tried to start the car to observe if the engine light was still there. I immediately observed a very long delayed start. The idle is moving slightly up then down until the car stalled. "

this is quoted from someone elses post with a bad title, so no one read it. My car is suffering from the same problem. i had a CEL for the Evap Canister, took care of it, and my car (i noticed when doing the Evap, is making a Rhythmic clicking when the ignition is in the On position, even if the car is not actually running. (full accesory mode). my car is also idling around 500 RPMs, and has stalled out a few times. Searching really didnt reveal any similar threads. Suggestions??

Thanks

 

Sounds like your IACV or Idle Air Control Valve isn't working properly. That valve controls your idle speed. It's a stepper type motor and thats how they sound. Your may be getting hung up thats why you hear is constantly trying to correct itself.

Do a search on here, you can take them apart and clean it up. That may stop it from acting strange and give you your smooth idle back.

One more thing - Now's a good time to clean your throttle body as well. www.motorvate.ca

 

I can't find the IACV in the engine bay. Where exactly is it located?

 

Attached to the throttle body. Sort of behind the TPS plugs.