01 dodge ram 1500 5.2

i have a 01 dodge ram 1500 5.2 with 140k on it. the truck has started to have a rough starting problem. once it does start and i shift into rev or net and step on the gas it wants to die unless a feather the pedal. it also revs up when taking off and doesnt want to shift right. once it shifts from 2 to 3 it down shifts and revs up until i feather the pedal. this all started at about the same time. i was told this my be a throttle position sensor causing all the problems. also have been getting crappy mpg.there are no codes or check engine lights on.