This is my second thread on this issue.I told u guys that I changed my battery after the old battery is goin to retire.Then,I started to get a low idle.I drove it already for few days..still same scenario.I plugged my OBD II SCAN and threw me a code P0172.So I decided to clean my throttle body and my idle sensor(IAC) thinking it might solved the problem..but guess what..it get worst!!!I can't drive it around anymore.Everytime I turn on the engine,my idle will be in 1800 position for few minutes then,it will go down and vary every now and then until it will stall. Brought it to the mech. he said that it might be ur idle sensor not functioning well?what do u think?how u will check the IAC if it busted or working properly?is this the real problem?I already checked the hose and wires..still the same problem.Will u advise me to go to the dealer(lexus) to get the proper diagnosis?please help!!need it badly.Thanks