P0308
Cylinder 8 Misfire Detected
Ignition / misfire
Generic OBD-II
High
What it means
P0308 means the engine is misfiring specifically on cylinder 8 — the fuel-air mix in that cylinder isn't igniting properly, so the engine runs rough and loses power. Because unburned fuel passes into the exhaust, a sustained misfire can overheat and ruin the catalytic converter, so it should be traced and fixed promptly.
High
Can I keep driving? Not for long — a misfire on cylinder 8 dumps raw fuel into the exhaust; drive as little as possible until fixed, especially if the check-engine light is flashing.
Common symptoms
What you'll notice
- Check-engine light on (may flash during an active misfire)
- Rough idle, shaking, or stalling
- Reduced power and hesitation on acceleration
- Engine runs unevenly, sometimes with a smell of raw fuel
Common causes
Most likely first
- Worn spark plug on cylinder 8Likely
- Failing ignition coil on cylinder 8Common
- Faulty or clogged fuel injector on cylinder 8Common
- Vacuum leak near cylinder 8's intake runnerLess often
- Low compression — worn valves, rings, or a head-gasket issueLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm the miss is isolated to cylinder 8.
- Inspect and replace the spark plug on cylinder 8 — the cheapest and most common cause.
- Swap the cylinder 8 coil with a neighbouring cylinder; if the misfire moves, replace the coil.
- Check the injector and fuel delivery to cylinder 8.
- If it persists, run a compression test to rule out a mechanical fault. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0308?+
No — especially with a flashing light. A steady misfire on cylinder 8 can quickly overheat and destroy the catalytic converter.
Can I just clear P0308?+
You can, but it returns within a few drive cycles until the cause of the cylinder 8 misfire is repaired.
Related codes
Often seen with P0308
Read & clear P0308 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX