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.