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Engine Misfire: Causes, OBD2 Codes & How to Find It

A misfire is when a cylinder fails to fire properly — you feel a stumble, shake, or loss of power, and the check-engine light may flash. It comes down to a missing ingredient in that cylinder: spark, fuel, or compression.

Is it safe to drive?

A flashing check-engine light means an active misfire that can damage the catalytic converter — stop driving and get it checked. A steady light with an occasional misfire is less urgent but still worth prompt diagnosis.

What to check first

  • A flashing light = active misfire; reduce load and get it diagnosed quickly.
  • Scan for the cylinder-specific code (P0301 = cylinder 1, etc.) — see below.
  • Swap-test ignition parts: move the coil/plug to another cylinder and see if the misfire follows.
  • Rule out fuel injectors and, less often, a compression / mechanical problem.

Most likely OBD2 codes for engine misfire

These trouble codes most often produce this symptom. Open one for its causes, fixes, and typical repair cost on your vehicle.

Typical repair costs

What the common fixes for this symptom usually run (parts + labor). Get an estimate for your exact vehicle free from the AI Mechanic.

spark plugs $150–$400 ignition coil $150–$400

Related reading: the full walkthrough on the blog .

Engine misfire: FAQ

What causes engine misfire?

A misfire is when a cylinder fails to fire properly — you feel a stumble, shake, or loss of power, and the check-engine light may flash. It comes down to a missing ingredient in that cylinder: spark, fuel, or compression.

Is it safe to drive with engine misfire?

A flashing check-engine light means an active misfire that can damage the catalytic converter — stop driving and get it checked. A steady light with an occasional misfire is less urgent but still worth prompt diagnosis.

Which OBD2 codes are linked to engine misfire?

Common codes include P0300 (Random or Multiple Cylinder Misfire), P0301 (Cylinder 1 Misfire), P0341 (Camshaft Position Sensor Range / Performance). Read a code's page for its specific causes, fixes, and cost.

Do I need an OBD2 scanner?

For a confirmed diagnosis, yes — a scanner reads the stored trouble code. You can triage many symptoms by behavior first, but the code is what pins down the cause. The free AI Mechanic can interpret your code and symptoms for your exact vehicle.

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