difuria

Thanks for your response. I have not cleaned the IAC. I have tried to locate it for the 02, but can't find a good picture or breakdown of it on the web. I have an idea where its at, but i'd like to see photos of the inside and outside before tearing things apart. Once I open it does it need a new gasket? Does it have a gasket? I assume I would clean it with something like carb cleaner to get the gunk off.

I have a 2002 ES300 with 115,000 miles on it. It runs good, except for the occasional jerky transmission and constant low idle issue. I realize the transmission is a flaw with the year and there's really nothing to do about it. I'm more concerned with the low idle. I started to notice the low idle last year with the air conditioning on. It idles at a round 450rpm. When the air turns itself off the idle raises to about 600 but slowly lowers to about 500rpm. The car runs a little rough around 450rpm, but smoother at 500rpm. Normal rpm is 500 with the air off. I've cleaned the throttle body numerous times. The rpm is around 750 after a good cleaning, but over the course of the day drops to its standard 500rpm. I've also reset the computer numerous times. It idles at about 750rpm after, but again drops to 500rpm. Has anyone else had this issue? Any suggestions on possible causes?