Hope someone can help. Have a misfire in cyl 5, but only at high RPM 3500-4000. Getting P0305 code.
Have had compression checked, new coils, plugs. Some carbon build up apparently in cylinder 5 as shop inserted scope w/camera.
Told I might have bad valve seat causing problem. Compression all in spec though? Running Lucas injector cleaner in gas to try and cleanup cylinder. Does this sound like valve problem or injector issue?? Any help appreciated.