Throttle body

Hey guys, recently every once in a while my car will idle below 500 rpm's and almost cut out, in fact, it's cut out once or twice. It doesn't do it all the time though. Several people have told me that it's a loose throttle body cable, which i was also thinking that was the problem, but a friend of mine told me that the throttle body is computer controlled and that you can't adjust it, anyone have any ideas??
Thanx

[ebpda9]

i think it might be the TPS sensor. have the tb clened out and see if anything happens.