I had my PCM unplugged and I plugged it back in yesterday and drove the car.

When I'm slowing down to a light the car idles very low to 500rpm. It should idle at 900 rpm with my cam. It corrects itself within a minute.

When I accelerate and let off it holds the rpm at 1500 for a long time before coming back down.

 

My car used to do that also, when I had the stock cam. To fix it, worked for me, disconect the battery cable and reset the pcm. When you plug it back up, dont do so until the car is completely cold. For some reason on my car, if I disconected the battery and reset the com. and cranked it with the car warm, the idle wouldnt flash up like it does when cold, and the computer would have the idle too low as it learned this setting. Hopes this works as it did for me.

 

Check this

http://shbox.com/1/4th_gen_tech2.html#iac_reset