So, it turned out to be the "APPS" sensor which they tell me communicates the gas foot pedal's location to the throttle system which digitally replaces what used to be accomplished with a simple throttle cable. Dealer tells me virtually all Dodge/Chrysler products use this technology now, even if different actual part SKU's are involved. There was a 2-week "national back order" for the part we needed, so the dealer scavenged the sensor from the showroom model. They say that Liberty's and Ram 1500's (my other vehicle, yay) have had these problems. The dealer had provided us with a new Jeep Liberty as a loaner, too. Although there was some hesitation and uncertainty on their part, overall, the dealer did everything they could to assist us. Reminding them that we have not yet completed our Daimler-Chrysler Dealership Questionnaire certainly helped! Now, if we could just get over the fear that the gas will suddenly fail sometime when we're about to turn left across oncoming traffic...