Check Engine P 304
 

I keep getting P304 on OBD2 . I have replaced plugs and Ignition wires and still happens every few days. PT only has 33000 miles . It is GT model HO Turbo. Any suggestions?

Could be a bad fuel injector on #4, or a problem with the valvetrain for same cylinder. Do a compression test, if #4 is lower than the other 3 cylinders, you are looking at some head work to be done. If OK, and you are getting rich running and gas dilution in the oil, or no spray at all,an injector problem. Wet or dark porcelain tip at the electrode, or totally white and looking like brand new would denote where the trouble lies.
Also did you stay with the factory recommended plus?

thank you for thread .

Coil pack as well