minivan keeps stalling

I have a 1991 Voyager that will stall when it wants. I've done a tune-up, replaced all of the exhaust except the catalytic, changed the fuel filter and cleaned out the throttle-body. It doesn't matter if I'm stooped at a light, idling or driving at various speeds. It will stall when it wants. If anyone has any clues please let me know. Any help would be appreciated. Thanks.

A few years ago, My 94 would stall coming to a stop sign. Took it in and turned out to be something called the Idle control switch or something like that. It is located somewhere around the throttle body. Just a thought.

Look in to the Cam Position sensor