P0300 Random/Multiple Cylinder Misfire Detected

Powertrain Severity: High Generic OBD-II

The engine computer detects misfires on more than one cylinder or cannot tell which cylinder misfires.

Common causes

  • Worn spark plugs or faulty coils
  • Vacuum leak
  • Low fuel pressure
  • Clogged injectors
  • Low compression or timing problem

Symptoms

  • Flashing or steady check engine light
  • Rough running
  • Shaking at idle
  • Loss of power

What to check

  1. A flashing light means stop driving hard - unburned fuel can overheat the catalytic converter
  2. Check misfire counters per cylinder
  3. Inspect plugs and coils
  4. Check fuel trims and pressure

Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0300, follow the service information for that make and model.

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