P0301: Cylinder 1 Misfire Detected
Severity: High
What it means
Cylinder 1 isn't firing properly. Cylinders P0302–P0308 work the same way for other cylinders.
Common symptoms
- Shaking at idle
- Hesitation when accelerating
- Flashing check engine light
Common causes
- Bad spark plug
- Bad ignition coil
- Clogged or failed fuel injector
- Low compression in that cylinder
What to check first
- Swap the cylinder 1 coil with a neighbor and see if the misfire moves
- Inspect the spark plug for wear or oil
Causes vary by vehicle. Confirm with testing before replacing parts.
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