OBD-II code guide
P0301 Cylinder 1 Misfire Detected
P0301 means the engine computer detected a misfire on cylinder 1.
What it means
Cylinder 1 is not contributing power consistently.
Common symptoms
- Rough idle
- Shaking
- Flashing check engine light
- Poor acceleration
- Fuel smell
Likely causes
- Worn spark plug
- Failed ignition coil
- Fuel injector problem
- Compression issue
- Vacuum leak affecting one cylinder
First checks
- Confirm cylinder numbering for the engine.
- Look for other misfire or fuel trim codes.
- Inspect the plug and coil for cylinder 1.
- Do not keep driving if the light flashes.