P0300
Get Serviced SoonFix: Urgent — address soonRandom/Multiple Cylinder Misfire Detected — Multiple cylinders are misfiring. Can cause rough idle, loss of power, and potential catalytic converter damage.
Dashboard light triggered
Check Engine LightWhat to do
If the light is flashing, reduce load and get scanned soon — catalytic converter could be at risk. If steady, schedule a diagnostic. Don't ignore.
Common causes
- Worn spark plugs or ignition coils
- Clogged fuel injectors
- Low fuel pressure
- Vacuum leak
- Compression loss (worn engine)
Estimated repair cost
$150–$1,200
Exact cost depends on the cause, your vehicle, and labor rates in your area.
What to tell your mechanic
Use this script so you sound informed and get a clear diagnosis before agreeing to repairs:
“Code P0300, random misfire. Can you identify which cylinders are misfiring and run a compression test if needed? I want to know if it's ignition, fuel, or something more serious.”
About the Check Engine Light
Code P0300 triggers the Check Engine Light. Indicates an issue with the engine or emissions system. Could range from a loose gas cap to a serious engine misfire.
Read full Check Engine Light guideFrequently asked questions
- What does OBD code P0300 mean?
- Random/Multiple Cylinder Misfire Detected — Multiple cylinders are misfiring. Can cause rough idle, loss of power, and potential catalytic converter damage.
- What dashboard light does P0300 trigger?
- P0300 triggers the Check Engine Light.
- How serious is P0300?
- Severity: yellow. Fix priority: Urgent — address soon.
- How much does it cost to fix P0300?
- Repair costs typically range from $150–$1,200. The exact cost depends on the root cause and your vehicle.
Related OBD codes (same dashboard light)
These codes also trigger the Check Engine Light: