1998 Saturn sc2. got stuck in snow tried rocking car to get it out didn’t work had to be pushed out. after that check engine light on and when i get to about 40 mph wont go in to overdrive. ran diagnostics came back with code PO734 gear 4 incorrect ratio. what does that mean? do i need a new tranny or are there other things i can do first to try and fix without having to replace tranny?