I have a 2002 Odyssey with 111+ K miles. It idles up to 2K RPM or above after driving in stop & go traffic in hot weather. Ok after cool down. Could this be caused by the IAC valve?

 

welcome to the forum. Yes good place to start.

 

After my previous post (above), I decided to try something I did before when I had a slow idle problem. The IAC (idle air control) valve is located in the bottom of the throttle valve assembly. It is an air bypass to the throttle plate. The more air it lets through the faster the idle. Less air slower idle. When I had the slow idle problem, I tested the IAC as per the shop manuel. It tested ok. B-12 spray has done wonders in the past to fix carburetor idle problems. So, with the air cleaner housing and intake tube removed, I sprayed a liberal amount of B-12 into the slot in the throtle body that leads to the IAC valve. Then started the engine and let it idle for a short time. I also checked to see that the cruise control cable was moving freely. We took about a 100 mile road trip yesterday combining slow traffic and highway driving. The outside temp was 95 to 100 degrees. The idle was normal at every stop. So far so good.

 

Good job, may be a good fix. Where might I be able to find this B-12 spray? Have not heard of this spary. Thanks.