12-25-2025, 04:57 AM
I'm dealing with a persistent engine misfire in my 2012 Ford Focus that's throwing a P0302 code for cylinder 2. I've already replaced the spark plugs and ignition coil pack, swapped the fuel injector with another cylinder, and checked for vacuum leaks, but the misfire remains. The car idles rough and has a noticeable loss of power, especially under acceleration. For experienced DIY mechanics, what would be your next logical steps in the engine misfire diagnosis? Should I be looking at compression test results, a possible faulty valve, or could it be an issue with the PCM or a wiring harness? I have a basic scan tool and a decent set of hand tools, but I'm trying to avoid just throwing more parts at it.