Engine dies when you step on the gas

I believe we are talking about two completely separate problems here:
1) The need to shift to neutral in order to start the car.
2) The car stalling when you rev it.

1) All modern automatic transmision cars have a safety switch that impedes the operation of the starter motor when the car is in any gear other than park or neutral. I believe it is called the neutral safety switch. Sometimes this switch can get out of alignment and cause this problem. As this witch is known to be in different places for different cars, I would recommend that you either see a mechanic to realign the switch, or learn to live with putting the car in Neutral before you crank it.


2) Let's think about this as a normal problem first:
It takes three things to have combustion:
1) Oxygen (in the form of air in this case)
2) Fuel (in the form of gas in this case)
3) An ignition point (in the form of a spark plug in this case)

The trick is getting these three variables in the right ratios, at the rigth times. Any of them is off (too much fuel, not enough air, spark too early or too late) and you have a failed combustion.

A car's internal combustion engine is no different. Reading your request, I think we can pressume that the engine actually starts and runs idle.

If this is the case, then check the following:
1) Change the air filter.
2) Drop in some injector cleaner into your tank.
3) If the above two fail, take the car to a mechanic and have them check the injector pressure. The problem may be related to the fuel pump not putting up enough pressure to rev the car, while only putting up enough pressure to idle the car.

Hope that helps!

Fuel system problem. possibly carbon build up in the what i assume is the throtlebody injection. maybe clogged fuel filter. try some fuel cleaners. if that doesnt work, take the injectors out and clean them thoroughly. still no dice, find the specs on the carborator/injection system and tweak with it.