First off address the codes that it is giving . If you have a bad )2 sensor it can affect your idle and drivibility. So if codes are happening that is where you need to start. The Iac circuit seems to say that you are reading higher then expected so could you have the TPS set a little too high whenyou changed it. It can be made to adjust and as I have said before I think it has a range of .5 volts to .9 volts when it is just sitting closed and will move upward from there when the trottle is opened. I know some have said the new cars use a different method of closed loop to reset this with each start, but maybe you should try and set this at the .5 volts when it is just closed and see if that helps. If it does make a difference but the way you want try moving it more to the .9 volts. This may well stop all those codes bu the O2sensor.