P0314 Single Cylinder Misfire (Cylinder Not Specified)

P0314 points to a single-cylinder misfire where the controller has not identified the cylinder number. The misfire pattern is specific enough to flag one hole, but not enough to assign it confidently.

Code details

Generic OBD-II · P0

System: Ignition / Misfire
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not treat P0314 as a random misfire; isolate the cylinder and root cause before clearing codes or replacing common ignition parts.

Symptoms of P0314

Rough idle, shaking, or a stumble under acceleration.
A flashing check-engine light during an active misfire.
Power loss and higher fuel consumption.

Common causes of P0314

Worn spark plugs, ignition coils, or plug wires.
Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
Vacuum leaks, low compression, or a mechanical fault in that cylinder.

Useful checks before replacing parts

Compare freeze-frame load, misfire counters, Mode 6 data, fuel trims, crankshaft variation learn status, and any companion fuel or ignition codes.
Inspect ignition output, injector operation, intake leaks, compression, valve timing, fuel quality, and harness issues that could affect one cylinder.
Use scan data and physical tests to narrow the affected cylinder before replacing coils, plugs, injectors, or sensors.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and pin down the fault area.