Low idle at start and intermittent stalling

At initial start up rpm's drop to about 150 then quickly rise to 850. As engine warms and seems to go into closed loop the idle rises and holds at 1,000. Seems to be doing the opposite of what it should do on a cold start up. It also stalls intermittently when coming to a stop but always starts again and runs if I keep my foot on the accelerator a bit. After driving again for about 10 min. It drives like a dream and may not stall for a couple of days. I have codes for running rich for both bank one and bank two. (Map, iac, tps, egr, fuel pump, fuel filter, pcv valve, intake manifold gaskets, and spark plugs have all been changed. Also fuel injectors have been pulled and cleaned along with cleaning throttle body)
Thank you for your help,
Drayton