Cavalier dies when put in gear?

Did this just start happening without any other symptoms and or problems? I know of one thing that will cause that on the Auto Trans Axle there is a solenoid that pulls in the TCC (Torque Converter Clutch)
this is only supposed to come in at certain speeds and drop back out when speed is reduced. When they stick on it mechanically locks the engine to the torque converter and input shaft of the transmission so when you put it in gear you have no stall which kills the engine immediately. Look for a plug on the trans axle it shoud have about 3 or 4 wires going to it just unplug it and then try it. If the engine keeps running after you place it in drive you will know that the solnoid is stcking.
This is mainly for emission and gas mileage so you can drive with it un hooked until you can have it repaired.

Good Luck!