Can someone help with my car trouble?

Hi, I have a 98 Pontiac Grand Prix GTP Supercharger. it's shutting off after a few minutes of running. it's reading a misfire in cylinder 6, but i changed plugs, wires, ignition control module, ignition coils,and the alternator. I use 93 octane gas and even put an injector cleaner in it. don't know what else to do, can anyone help?