Please please please help me!! I miss driving my GTP!!

I have a 2002 Grand Prix GTP, and I put a new head gasket set in it. After I got the motor put back together I cycled the key, and started the car. I let the car run to get all the air out of the lines and once everything was settled it ran fine. I test drove it with no problems, and then parked it for a few days. after the few days i drove give or take 12 miles and the car started to miss on cylinder 1, and i began to hear a tick. the tick is not constant. and when i have the car running every time it ticks the boost bypass actuator moves. when i discovered the car was having a miss i changed the plugs, wire, coil packs, ign. module, but its still missing on cylinder one. when the injector for cylinder 1 is plugged in it missed bad. when i unplug injector 1 it runs smoother and the tick stops. i swapped injectors with cylinder 3 and the miss is still on cylinder 1. could it be low compression, bent valve, injector connector, the wiring? i need help bad!