P0310 — Cylinder 9 Misfire Detected
Drivable short-term, but fix now to avoid damage.
What P0310 means
This code means your engine's computer detected a misfire in cylinder 9, so that cylinder isn't completing its combustion the way it should. It's typically caused by worn spark plugs, a bad ignition coil, fuel injector issues, or low compression. The repair usually starts with replacing spark plugs and coils, and it's a common problem that's often fixable without major engine work.
Common symptoms
- Check engine light is on or flashing
- Rough idle or engine vibration
- Loss of power during acceleration
- Engine hesitation or stumbling
- Worse than normal fuel economy
Common causes
- Worn or fouled spark plug on cylinder 9
- Faulty ignition coil for cylinder 9
- Clogged or failing fuel injector
- Vacuum leak or low compression in the cylinder
- Damaged spark plug wires or connectors
Typical repair cost
$150 – $1200
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0310 code?
Only briefly if you must. A misfire can harm your catalytic converter and worsen quickly, particularly if the light is flashing. Get it diagnosed promptly.
How much does it cost to fix a P0310 code?
Expect roughly $150 to $1,200 depending on the cause. Spark plugs and coils are on the cheaper end, while injector or compression repairs cost more.
Is a P0310 code serious?
Yes. Misfires reduce performance, waste fuel, and can damage emissions parts over time. A flashing check engine light raises the urgency.
Note that high cylinder numbers like 9 mean a big engine?
Yes, cylinder 9 only exists on engines with many cylinders, like V10s or V12s. On these engines, parts can be pricier, so accurate diagnosis before replacing anything saves money.