OBD2 code P0301: Cylinder 1 Misfire Detected
The engine module detects misfire from crankshaft speed: a cylinder that does not fire gives no acceleration impulse.
Detected Root Component
Powertrain Component
Observed Symptoms
- Check engine light on, flashing at a catalyst-damaging rate
- Rough idle, jerking, vibration
- Loss of power, hesitation
- Smell of unburnt fuel, higher consumption
Possible Causes
- Ignition coil of cylinder 1 faulty (coil, connector, ground)
- Spark plug of cylinder 1 worn, sooted, cracked or wrongly gapped
- Injector of cylinder 1 clogged or leaking, or its control
- Low compression on cylinder 1 (valve, rings, head gasket) or local false air
- Water or oil in the plug well
Tools Required
Interactive Diagnostic
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Parts likely to be the cause (Allumage / Bobine)
Allumage / Bobine
Photo d'illustration : Allumage / Bobine
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Frequently asked questions about code P0301
What does code P0301 mean? ▾
OBD2 code P0301: Cylinder 1 Misfire Detected. The engine module detects misfire from crankshaft speed: a cylinder that does not fire gives no acceleration impulse.
What are the symptoms of code P0301? ▾
Code P0301 may cause: Check engine light on, flashing at a catalyst-damaging rate, Rough idle, jerking, vibration, Loss of power, hesitation, Smell of unburnt fuel, higher consumption. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code P0301? ▾
The most common causes of code P0301 are: Ignition coil of cylinder 1 faulty (coil, connector, ground), Spark plug of cylinder 1 worn, sooted, cracked or wrongly gapped, Injector of cylinder 1 clogged or leaking, or its control, Low compression on cylinder 1 (valve, rings, head gasket) or local false air. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code P0301? ▾
Yes, code P0301 is critical (Critical). Avoid driving and consult a professional promptly to prevent major damage.
How do I fix code P0301? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Ignition coil of cylinder 1 faulty (coil, connector, ground), Spark plug of cylinder 1 worn, sooted, cracked or wrongly gapped, Injector of cylinder 1 clogged or leaking, or its control, Low compression on cylinder 1 (valve, rings, head gasket) or local false air. Difficulty: Medium · Estimated time: 30-60min.