OBD-II code guide

P0305 Cylinder 5 Misfire Detected

P0305 means the engine computer detected a misfire on cylinder 5.

What it means

Cylinder 5 is not contributing smoothly because combustion is incomplete or irregular.

Common symptoms

  • Shaking
  • Rough idle
  • Flashing check engine light
  • Poor acceleration
  • Fuel smell

Likely causes

  • Spark plug or coil problem
  • Injector issue
  • Compression problem
  • Vacuum leak near cylinder
  • Wiring fault

First checks

  • Avoid driving with a flashing light.
  • Compare coil, plug, injector, and compression data.
  • Check for fuel or coolant intrusion signs.
  • Use cylinder-specific testing instead of guessing.