OBD-II code guide

P0308 Cylinder 8 Misfire Detected

P0308 means cylinder 8 is misfiring often enough to trigger a trouble code.

What it means

Cylinder 8 has incomplete combustion or inconsistent power contribution.

Common symptoms

  • Rough running
  • Shaking under load
  • Poor power
  • Flashing check engine light
  • Possible catalyst smell

Likely causes

  • Faulty coil
  • Worn spark plug
  • Injector fault
  • Low compression
  • Vacuum or intake issue

First checks

  • Record all misfire codes.
  • Confirm cylinder numbering before replacing parts.
  • Check plug, coil, injector, and compression clues.
  • Do not keep driving with a severe misfire.