Car worked perfectly until I tried starting it one night at Wal-Mart. As soon as I turned the key the car started and then stalled, after shifting to reverse. Turned the key again, but this time it wouldn't start? I somehow managed to get it to a shop and we replaced the starter. It starts fine now, but for some reason it still shuts off when I put it in reverse. It shuts off about 2-3 seconds after putting it in reverse, regardless of what I do. Car runs great other than that.
Car shuts off in... reverse? on 1997 Saab 900
It sounds like your trans computer is malfunctioning. I recommend having a Saab dealership or Saab specialist diagnose and repair the car for you. I recommend a specialist or dealership because earlier Saabs are, well, a different breed of car.