hi i drive an omega 2.6 cdx auto with a v6 engine the problem i am having is that every so often the car revs and gets stuck in 3rd i have to pull over and turn the engine off for a few seconds then restart the engine and the car drives ok

....any ideas someone said it could be speed sensor or gearbox sensor?


also how do i get the code for my radio i never got it with the car when i bought it 3 months ago...i went back to the person i bought it from but he did not have it either...pleaseeeeee helllppp...