I have a 99 GA with 127*** miles on it when i am going down the road with the gas held steady the trans goes in and out of gear its an automatic but it doesnt feal like its sliping it feals like its in neutral it takes off fine and didnt do it all the time but is happining more often the service light was on when the problom started and autozone said it was something stuck in the trans(solinod or switch?) where do i start? Thanks Danny