OBD-II code guide

P0307 Cylinder 7 Misfire Detected

P0307 means the engine computer detected a misfire on cylinder 7.

What it means

Cylinder 7 is not burning the air-fuel mixture consistently.

Common symptoms

  • Rough idle
  • Engine shaking
  • Poor acceleration
  • Flashing check engine light
  • Fuel smell

Likely causes

  • Spark plug wear
  • Ignition coil fault
  • Injector issue
  • Compression problem
  • Wiring or connector issue

First checks

  • Confirm the engine has a cylinder 7 and verify numbering.
  • Check for related P0300 or fuel trim codes.
  • Inspect ignition and injector connectors.
  • Avoid driving hard with a flashing light.