P0300 Pontiac -number 2 and 5 cylender misfire

Question

changed spark plugs and wires ignition coils and
still have misfire on 2 and 5 cylinder

Answer 1

the injectors might be clogged or bad. You can try using a fuel system cleaners.

you can also check the resistance of the injector of other injectors and compare them cylinder 2 and 5.