I have been trying to nail down my hanging idle and got close today but i think in the end it has to do with a IAC that is not functioning very well (or at all for all i know). I had been able to adjust the idle down to 450 with my old TPIS chip following the procedure to get the car in diagnostic mode with the paper clip across a-b. Well with the tune that is in there now i could not for the life of me get the car to idle down past 900 with the IAC unplugged and following the paper clip procedure. There is either one of two things going on...im not getting the IAC to fully extend and close for some reason..or the IAC is busted and wont fully close anymore.

I took the throttle body off and took the IAC out and cleaned it and it wasnt all that bad. I put it back together and i can literally back the idle screw out all the way to the point its not touching the throttle plates anymore and the car will STILL idle at 900 or so. Im stumped.

So i guess my question is..is there a way to make sure it got into diagnostic mode at all? My check engine light from what i understand should have been on when in diagnostic mode and it wasnt....

If i was really in diagnostic mode then i think its time for a new IAC. I think this one is original to the car anyways.

Oh and to top it off there is a good deal of play in my throttle body shaft. I might be looking at a new one of those too.