All codes
P0306Engine Problems
Cylinder 6 Misfire Detected - Diagnosis Guide
Complete guide to the P0306 cylinder 6 misfire code, including symptoms, common causes, and step-by-step fixes.
What you may notice
Symptoms
- 01Check engine light on or flashing
- 02Rough idle
- 03Reduced power
- 04Increased fuel consumption
- 05Possible exhaust popping
Where to look first
Common causes
- 01Worn spark plug in cylinder 6
- 02Faulty ignition coil
- 03Fuel injector fault
- 04Vacuum leak affecting cylinder 6
- 05Compression loss in cylinder 6
Step by step
What to check and repair
- 01Replace the cylinder 6 spark plug
- 02Test and replace the ignition coil if faulty
- 03Inspect and service the fuel injector
- 04Check for vacuum leaks
- 05Run a compression test if needed
What Does P0306 Mean?
The P0306 code means cylinder 6 is misfiring. The ECM monitors crankshaft speed and flags cylinder 6 when it isn't contributing its share of power.
Common on V6 and V8 Engines
Cylinder 6 misfires are frequently ignition-related. On higher-mileage engines, a single weak coil or worn plug on that cylinder is the usual culprit.
How AI4Car Helps
AI4Car lets you watch live misfire data and fuel trims so you can tell whether the cause is ignition, fuel, or a mechanical compression issue.