alright so i just got back from advanced auto parts

heres what i got

p0306
cylinerd 6 misfire detected

where do you all think i should go from here

Mystique 98 ls T-red MTX B&G springs Turbendz y-pipe (running test pipe) Trubendz cat back with flowmaster muffler Costume intake with K&N filter B&M shifter Magstar wires