Trouble codes › P0302

P0302 Cylinder 2 Misfire Detected

Ignition and misfire

P0302 means cylinder 2 is misfiring, usually from a bad spark plug, ignition coil or fuel injector on that cylinder.

The engine computer has seen cylinder 2 fail to fire often enough to set a code. Which cylinder is number 2 depends on the engine; your service information or an owner forum shows the layout.

Can I keep driving? Not if you can avoid it.

If the check-engine light is flashing, stop driving as soon as you safely can to protect the catalytic converter. With a steady light and a mild miss, drive gently and get it fixed soon.

Common causes

  1. A worn or fouled spark plug in cylinder 2
  2. A failing ignition coil or plug wire on cylinder 2
  3. A clogged or leaking fuel injector on cylinder 2
  4. A vacuum leak near cylinder 2's intake runner
  5. Low compression in cylinder 2 (less common)

Symptoms

  • Rough idle or a steady shake
  • Loss of power, hesitation
  • Flashing or steady check-engine light

Known problems: GM V8 AFM/DFM lifter failure · 5.7L Hemi lifter and camshaft wear ("Hemi tick") · Honda 3.5L V6 VCM misfires and fouled spark plugs

What to check first

  1. Swap the cylinder 2 coil with a neighboring cylinder, clear the code and drive. If the misfire follows the coil, replace the coil.
  2. Pull and inspect the spark plug for oil, carbon, cracks or a worn gap.
  3. If coil and plug are fine, check the injector and look for vacuum leaks near that cylinder.
  4. Still misfiring? A compression or leak-down test shows whether it's mechanical.

What does P0302 mean on your vehicle?

The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.

Ask iRepair about P0302

No scanner? Most auto parts stores read check-engine codes for free.

Related codes

General guidance for P0302 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.