My 1999 grand prix stalls and dies at stops.

run fault codes to find which sensor has become faulty and put the engine in limp mode.. Check oil and coolant levels

If you are saying the engine will not crank, try it in neutral instead of park.
The neutral safety switch could be faulty, or you could have a problem with the starter solenoid on the starter.

Have you checked your air filter a clogged air filter will cause your car to die when idleing. You could idle up the engine a bit if that does't help.A bad o2 sensor could also be the culprit. Start with the easiest first and go from there.

Please include engine and mileage to help with answers. There is a sensor in the tube connecting the air box to the throttle body. Map, mass air flow sensor. It is delicate and pricey. The auto parts has a aerosol can of cleaner for about 8$ designed to clean this part. Carefully remove it from the tube housing and spray it off with the cleaner. This cleaner will attack the plentum and tube melting it causing air leaks if you use it in the tube. On a 3800 If you have coolant leaks or seeping check the plenum it may need to be replaced if it has not already been. They have a new style that is reinforced. This should smooth out the idle and clear up stalling if it's dirty. Air leaks can also cause an unstable idle and stalling at stop signs. Anti freeze can turn corrosive and should be changed. I change mine about every 3 or 4 years. Make sure if your engine contains aluminum parts ( block or heads) that you use the correct antifreeze when refilling or adding to existing levels. Green or orange. Read the label to make shure the product is correct for your car.

map sensor it is located in between the coils and the intake plenum

There should be a slot next to the shifter you can push your key into to get it out of park. Put it in neutral. Then start the car. That should get you home.

Have you tried replacing the O2 Sensor or Mass Airflow Sensor?

provided you don't have a vacuum leak, (check all hoses for tightness and cracks with engine running) it's probably your idle air control valve or sensor.

Hello and yes this is a major noise. I would check your oil now right before you ever start the oil again. This noise may have been your engine locking up from really low oil levels and excessive heat from a lot of driving. If this is fine contact me again and we will address more problems if their is more. Thank You.

When it stalls, does it start back up and then die again when you put it in drive or just not start back up?