With intermittent problems all those tests are meaningless if they aren't done while the problem is occurring. You have to clarify too how the symptoms act. Does the engine stall suddenly as though you turned off the ignition switch or does it sputter for a few seconds, then gradually lose power?

If the stalling occurs more often when you start to coast from highway speed, you might suspect a plugged strainer in the gas tank. You can also drive the car with a scanner connected that has a record feature. I use the Chrysler DRB2 and DRB3 for all of my newer cars. They will show the status of the automatic shutdown (ASD) relay. If that turns off when the stalling occurs but before the engine coasts to a stop, a failing sensor is the most likely suspect. There should also be a diagnostic fault code stored in the Engine Computer that will identify the circuit or system with the problem.