I've got a 1997 Cutlass Supreme sedan. A new quirk is with the transmition cutting out from 'drive'. It only happens when the car is being driven before it has a chance to warm up. Sometimes, I can shift from drive to park and back, then it will engage. Other times, I need to shift to park, shut off car, and restart before drive will engage. Do you think this is a sensor problem that can be easily repaired my myself, or is it something else entirely?