My truck often idles really low especially when the engine hasn't warmed up yet. It will stall if it is in drive, but not park or neutral. I have changed oil, oil filter, transmission fluid, fuel filter, cleaned the egr valve, mass airflow sensor, and the throttle body recently. Only thing I was going to do in addition to all those was clean the idle air control valve, but the screws were on too tight for the crappy screwdriver I was using.
I have the screw that controls the idle almost all the way loosened.
The idling isn't too much of a problem once it is warmed up, but I can tell that it could be better.

Any other things I could do or check??? (I know stuff like the atf has nothing to do with idling just mentioning it)