P0306 Pontiac - g6 gt 3.5

Question

I have changed the coil and spark plug and wire

Answer 1

P0306 Misfire cylinder number 6

This leaves you with fuel injector being the cause , or a mechanical condition of the number 6 cylinder.If the fuel injector connection is not properly mated , this can casue a misfire, a leak down test and a compression test of number 6 cylinder should be made.