I have a 1996 monte carlo. When we first got it a year ago you had to push the floor shifter ahead a little to get it to go into overdrive. Now it has quit going into over drive. the check engine light came on. we checked the code, and it was transmission range control sensor. anyone have an idea what is wrong?

Yeah sounds like you might need some intensive tranny work! Try loosening the vaccum module on the tranny! Not to much just slightly tight! if that does nothing then start looking for a good shop!