hey need help on turbo set up
 

I have an ls turbo in an eg si. The ls has wisceo pistons, eagle rods, 440 injector and have neptune as my tuning. The problem is that there is a miss fire which i can't understand why, I changed the spark plugs and plug wires. I need something to go on so give me as much info to try to figure it out. Also the it has 68 mm tb and an aftermarket intake. The turbo is a t3 t4 garett. Plus the i have a catch can home made that goes from the little canister that is in back of the block directly to the catch can with now check valve and also the top of the ls head to the catch can if that makes any sense.