2003 Grand Am Cylinder 4 Misfire

[samantha1122]

I have a 2003 Grand Am GT with the 3.4 motor that is skipping. When it is scanned it say "Cylinder 4 Misfire". I have replaced plugs, wires, and the coil pack. What else could be causing this? Have been told the next things to check are the Oxygen Sensor and the injectors, can anyone tell me if this is correct or not?

 

[Zimgxp]

The O2 sensor will not cause a missfire. Injectors and compression are the two remaining things to check.

 

[samantha1122]

Thanks so much!