I purchased a 1999 Grand Prix GT about 6 months ago, ran great, but recently I have been having trouble keeping it running. I would get it started then when I come to a stop the rpms would go to 0 then the engine would shut off. At times I would put it in nuetral and floor the gas, even then the car would sputter and the rpms would bounce from 6 to 2 and then 0 and it would shut off. I had the check engine light on and it was for a bad mass air flow sensor which I replaced. Can anyone shed some light on this for me?

Mass air flow sensors are very sensative to chemicals, heat, dropping while removing to service air plenum and just plain touching them internally. Maybe it just was its time to be replaced. Age or mileage will catch up with any vehicle. Heat andvibration over time are electronics biggest killers. Fortunately stock MAFS are inexpensive compared to the aftermarket Granatelli and JET.:D