P0300: Random / Multiple Cylinder Misfire Detected
The engine computer noticed cylinders firing unevenly across more than one cylinder. You'll usually feel a shake at idle, lose power, and see the check engine light flash on hard acceleration.
Can I keep driving?
If the check engine light is flashing, stop driving as soon as it is safe. A flashing light means misfires heavy enough to damage the catalytic converter. A steady light usually allows gentle driving to a shop or parts store.
Symptoms you might notice
- Shaking or a rough, uneven idle
- Hesitation or loss of power when you accelerate
- Check engine light that flashes under load
What to check first
- Read all stored codes. If P0301 through P0308 are also there, one cylinder is the main culprit and you can start there.
- Check the age of the spark plugs and coils. Worn plugs are the most common cause of a random misfire.
- Listen for a hissing vacuum leak and inspect the intake boot and PCV hose for cracks.
- If plugs and air are fine, test fuel pressure and look at the injectors before suspecting engine compression.
Most common causes
- Worn spark plugs or ignition coils
- Vacuum leak (intake gasket, PCV hose)
- Weak fuel pump or clogged injectors
- Low compression in multiple cylinders
Check it against your exact vehicle
A code means the same thing on every car, but where the parts are and what to check first depends on your year, make, model and engine. Tell CaliperAI what you are seeing and it will help narrow down the likely causes for your vehicle.
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General information about this code, not a diagnosis of your specific vehicle. Safety-critical work such as brakes, fuel and airbags is best left to a qualified mechanic.