P0307
Cylinder 7 Misfire Detected
Ignition / misfire
Generic OBD-II
High
What it means
P0307 means the engine is misfiring specifically on cylinder 7 — fuel isn't burning properly in that cylinder, so the engine runs rough and loses power. Because unburned fuel reaches the exhaust, a sustained misfire can overheat and damage the catalytic converter.
High
Can I keep driving? Not for long — a misfire on cylinder 7 dumps raw fuel into the exhaust; drive as little as possible, and stop if the light is flashing, to protect the catalytic converter.
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
- Increased fuel consumption
Common causes
Most likely first
- Worn spark plug on cylinder 7Likely
- Failing ignition coil on cylinder 7Common
- Clogged or leaking fuel injector on cylinder 7Common
- Vacuum leak or low compression affecting cylinder 7Less often
- Wiring or connector fault at the coil or injectorLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm the miss is isolated to cylinder 7.
- Inspect and replace the cylinder 7 spark plug if worn or fouled.
- Swap the cylinder 7 coil with a neighbour to see if the misfire follows it.
- Check the injector and its wiring, then test for vacuum leaks near that cylinder.
- If it persists, run a compression test on cylinder 7. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0307?+
Only briefly. A sustained misfire can quickly overheat and damage the catalytic converter, especially if the light is flashing.
Can I just clear P0307?+
It returns within a few drive cycles until the cause of the cylinder 7 misfire is repaired.
Related codes
Often seen with P0307
Read & clear P0307 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