for a few months now when i go to start my 2002 GT it turns over for like 5-8 seconds and then sputters a little bit and then starts for a little bit and then dies. If you try and start it again it does the same thing and then starts and stays running. It will stay running the first time if i give it gas once its started. It will start right up after the first turn if its really cold out. I thought it was the O2 sensor at first but it isnt throwing any codes. Anyone have any ideas?