96 Passport Low Idle

Occasionaly my 96 Passport will not idle. If I take my foot off the gas pedal in nuetral the engine will die. When driving I have to keep my foot on the gas pedal to keep it from dying when I come to a stop or driving down a hill. This happens once a week or so, have not been able to determine a pattern. It does it when the engine is warm or cold. On some rare occasions the engine would idle very high 1500 to 2000 RPM but that has not happened for a couple of months. I replaced the EGR valve about a year ago and cleaned out the tube with BG cleaner as I read on this forum. The car runs great other than the idle.
Details:
96 Passport LX
3.2L V6 4WD Auto Trans
150K Miles

You may need to remove and clean the IAC. A sluggish or stuck IAC will exhibit the symptoms you describe. It takes only a little varnish accumulation to stop an IAC. The uuper photo is what a "dead" one looks like, and the lower photo shows all that is necessasry to have a completely active IAC:

http://72.19.213.157/files/IACCompare.jpg

Thanks for the tip. I will assume the IAC is the idle air control valve located on top of the manifold next to the throttle? What do you use to clean it? Carb cleaner?