P0309
Serious Severity (Level 4)Cylinder 9 Misfire Detected
OBD-II diagnostic trouble code P0309indicates a fault detected by the vehicle's onboard computer. This code applies to all OBD-II compliant vehicles and should be addressed promptly to avoid potential engine or emissions system damage.
Severity Level 4 — Serious
This code indicates a serious issue that can cause noticeable driveability problems and potential engine damage if not addressed. The vehicle should be taken to a mechanic as soon as possible. Extended driving is not recommended.
Common Symptoms
- Check engine light on
- Reduced fuel economy
- Possible rough idle or hesitation
Possible Causes
- Cylinder 9 Misfire Detected
- Manufacturer-specific condition
- Fault in related component or circuit
Common Fixes
- Diagnose with professional OBD2 scan tool
- Check manufacturer TSBs
- Inspect related components per service manual
Estimated Repair Cost
$150 – $800(typical range; varies by vehicle make and model)
These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.
Explore Repair Costs
Worried about repair costs?
Get transparent estimates and verify your mechanic's quote before authorizing repairs.
Related Discussions
See what other car owners are saying about this code and related repairs.
View P0309 discussions in the community