Idle changes as I drive

[Philsnotfalling]

Last weekend a friend and I adjusted the timing, tps sensor, and replaced spark plugs. We used a snap-on scan tool. I have a new idle air control valve on the car, but the check engine light is on... iacv code. however the car idles and drives fine. we adjusted everything and had the idle set at bout 800. later on in the week my idle dropped from 800 to 500, it wanted to die. So I adjusted the idle back to 800... this morning my car went to 1500 rpms at idle. and here at the end of the day I was at 1200 rpms. and I just adjusted it back to 850. Has anyone had this problem before? Any suggestions?

[Philsnotfalling]

bump and update

today I'm at 900 rpms. mostly. soemtimes 1200 rpms.