1993 Plymouth Voyager Can it be the throttle position senso

I have a 93 grand voyager, just had the tranny replaced. But even before we replaced the tranny the van would (every now & then) drive high like it was stuck in one gear. Had no problems since we replaced the tranny, the other day I drove off without time to let the car warm & when I pulled into my destination the engine was running high & when I parked it with no foot on either gas or brake. The engine was just revving & the van kinda bucked forward. Turned off the van for a minute then restarted it & drove back home it ran fine! My dad said it could be the linkage needed lubricated & he sprayed it with some. He said it might also be the throttle position sensor, I called & it's only $32. The vans older so I may as well replace it to be on the safe side. Any other suggestions? It has been serviced, new air filter, fuel filter, oil change, etc.