P0309: Cylinder 9 Misfire Detected
CriticalPowertrainIgnition System
What does P0309 mean?
P0309 is a diagnostic trouble code indicating "Cylinder 9 Misfire Detected". One or more engine cylinders are not firing correctly, which can cause rough running, loss of power, and increased emissions. Continued driving with active misfires can damage the catalytic converter.
Common causes
- Worn or fouled spark plugs
- Failing ignition coil
- Clogged or leaking fuel injector
- Low fuel pressure
- Vacuum leak near the intake manifold
- Low compression in the affected cylinder
What should you do?
This is a critical issue. Stop driving as soon as it is safe to do so and have the vehicle inspected immediately. Continuing to drive could cause further damage or pose a safety risk.
Get a diagnosis for YOUR car
Code P0309 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.