My 2003 focus 2.0 L SOHC starts and runs fine on the highway but when I stop the engine stalls and takes about 5-10 minutes to start again. Worst of all it does not happen all the time. I have replaced plugs, wires and ignition coil.
Could this be the idle air control valve, fuel pump, bad gas or what?
Please help.

 

Some additional information.

When car stalls it is in park. Does not stall while in gear. Only happens after car has been driven about 15 minutes to get hot.