Thanks for help. My 01 RX300 had trouble with idle and low rpm idle too. Cleaned the idle control valve as instructed and works great. A little note for first timers, use a #3 philips screw driver for the 3 screws on the throttle body. Be prepared for coolant to leak out, I had about a quart of coolant leak from the hose line. Maybe it was because the car engine had been run. I did have to buy 3 new screws from the dealer, as mine were a worn out.
Ok so I followed the instruction posted by 'oldrx300' and the problem is still here. Now I noticed in the picture that 'RX300BILLY' posted he took apart the whole assembly not just the IACV. Is this what I'm supposed to do? Any help will be greatly appreciated. Thank you.