hi everyone i have a 1998 voyager le 3.3 auto, its started playing up with the gear and wont change up and shifts roughley, i have a scanner and plugged it in im getting codes po715 + po732 + po733 if i erase them it will drive for about a mile and then the transmission seems to bang and then its gutless and wont change up at all just revs highly, any ideas will be great??