P0306 Cylinder 6 Misfire Detected

P0306 indicates a detected misfire on cylinder 6. The named cylinder narrows the search, but diagnosis still needs data under the conditions that set the code.

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 keep driving with an active cylinder 6 misfire; raw fuel in the exhaust can overheat and damage the catalyst.

Symptoms of P0306

Rough idle or a distinct shake, often worse at low RPM.
A stumble or dead spot traced to cylinder 6.
A flashing check-engine light when the misfire is active.
Slight power loss and worse fuel economy.

Common causes of P0306

A worn spark plug or failed ignition coil on cylinder 6.
A clogged, leaking, or dead injector on cylinder 6.
A vacuum leak or low compression local to that cylinder.
Carbon-tracked plug boot or damaged coil wiring.

Useful checks before replacing parts

Review misfire counters and freeze-frame data to see when cylinder 6 misfires.
Inspect plug, coil or wire, injector, compression, valve sealing, local intake sealing, and harness condition.
Confirm any repair by repeating the same load, RPM, and temperature range that originally triggered the code.

Related OBD-II codes

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