Super high idle

Since you're running an aftermarket chip, do you know what the programmed idle RPM is? 750 RPM doesn't sound out of the realm to me.

It's set for 850 but it was the IAC setup that was getting me with its 500 +/_ 50 target.
Essentially what you need to do is set your throttle body opening to meter the largest portion of the idle air and let the IAC fine tune the idle RPM depending on the load ie: P/N vs D, A/C demand etc. Disregard 500 RPM initial set point as that only applies if the car is stock not modified. Once you find the correct combination your IAC counts will be in the low teens in P /N at operating temp.