P0300 – Random or multiple cylinder misfires detected

P0300 reports random or multiple combustion misfires. It does not identify one cylinder conclusively and does not automatically mean an ignition coil has failed.

Powertrain · Combustion and engine running

Open this code in the decoder

Meaning and affected system

A misfire means a combustion event does not make its expected contribution to engine operation. Monitoring systems can assess changes in crankshaft rotation. Cylinder-specific codes and misfire counters help identify the pattern.

Possible causes

On spark-ignition engines, worn plugs, damaged ignition components or their electrical supply can contribute.
An incorrect air-fuel mixture can disrupt combustion.
Further checks depend on associated codes and measurements; P0300 provides no universal parts-replacement sequence.

Possible symptoms

Hesitation or uneven running may occur intermittently.
Some misfire conditions cause a flashing check engine light; follow the vehicle handbook’s instructions.

Useful diagnostic considerations

Record whether the problem occurs at a cold start, at idle or under load.
Have misfire counters and cylinder-specific faults assessed alongside fuel-mixture readings.
Do not continue experimenting on the road with severe shaking or a flashing light; stop safely and follow the handbook or seek roadside assistance.

What this code does not prove

Detecting a misfire is not the same as identifying a faulty spark plug. Unburnt fuel can affect exhaust aftertreatment, so accompanying P0420 also needs context.

Look up another fault code

Sources and interpretation

This explanation was editorially cross-checked against the technical sources below. Manufacturer documents concern particular vehicle applications; their thresholds and repair procedures must not be applied universally.

OBD-II code data: OBDex (CC0 1.0) · 196fddffb6ef

Editorial source review: 16 October 2026.

The causes listed are possibilities without a likelihood ranking. This page cannot replace diagnosis of the vehicle. A code alone confirms neither a failed component nor that continuing to drive is safe. The actual condition, warnings, handbook and applicable manufacturer diagnostics determine the next step.