P0320 — Cylinder 12 Misfire Detected
Drivable short-term, but fix now to avoid damage.
What P0320 means
This code means your engine's computer detected a misfire in cylinder 12, so that cylinder isn't completing its combustion correctly. It's usually caused by worn spark plugs, a bad ignition coil, fuel injector trouble, or low compression in that cylinder. Repairs typically start with new spark plugs and coils, and it's a common issue 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
- Poor fuel economy
Common causes
- Worn or fouled spark plug on cylinder 12
- Faulty ignition coil for cylinder 12
- 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 P0320 code?
Only for a short distance if you must. A misfire can damage your catalytic converter and worsen quickly, especially with a flashing light. Get it diagnosed as soon as possible.
How much does it cost to fix a P0320 code?
Most repairs fall between $150 and $1,200. Spark plug and coil replacements are cheaper, while injector or compression repairs cost more.
Is a P0320 code serious?
Yes. A misfire reduces performance, wastes fuel, and can damage expensive emissions parts if left unaddressed. A flashing light makes it urgent.
Isn't P0320 sometimes about the crankshaft sensor instead?
On some vehicles P0320 relates to the ignition or engine speed input circuit rather than a cylinder 12 misfire, so the exact meaning can vary by manufacturer. A proper scan tool reading the manufacturer-specific definition is the safest way to confirm what your car means.