P0307 — Cylinder 6 Misfire Detected
Drivable short-term, but fix now to avoid damage.
What P0307 means
This code means the engine computer detected that cylinder 6 is misfiring, so the air-fuel mixture isn't igniting properly on that cylinder. It's most often caused by a worn spark plug, a failing ignition coil, or a faulty fuel injector, with vacuum leaks or low compression as other possibilities. Typical fixes are replacing the spark plug or coil for cylinder 6, and it's usually repairable without major engine work.
Common symptoms
- Check engine light is on or flashing
- Rough idle or engine shaking
- Reduced power and slow acceleration
- Engine stumbling or hesitation
- Poor fuel economy and rough running
Common causes
- Worn or fouled spark plug on cylinder 6
- Failing ignition coil for cylinder 6
- Clogged or faulty fuel injector
- Vacuum leak near cylinder 6
- Low compression from worn valves or rings
Typical repair cost
$100 – $500
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0307 code?
Only if you have to, and not far. A misfiring cylinder 6 sends raw fuel into the exhaust and can quickly damage the catalytic converter. If the light flashes, stop and tow the car; if it's steady, drive gently straight to a shop.
How much does it cost to fix a P0307 code?
Usually $100 to $500. Replacing a spark plug or one ignition coil is cheap, while an injector or compression-related fix runs higher. Pinning down the exact cause first saves money on unnecessary parts.
Is a P0307 code serious?
Yes, because misfires can overheat and ruin the catalytic converter, which is costly to replace. Fortunately the underlying cause is often an inexpensive, common part, so prompt repair keeps costs down.
Should I replace all spark plugs or just cylinder 6's?
If your plugs are old or high-mileage, replacing the full set at once is often smart since the others are likely near the end of their life too. If they were recently changed, replacing just cylinder 6's plug or coil may be enough.