P0301: Cylinder 1 Misfire Detected
Cylinder 1 specifically is misfiring. Swap the coil and spark plug from cylinder 1 with another cylinder — if the code follows the part, you found it.
Can I keep driving?
If the check engine light is flashing, stop driving as soon as it is safe. A flashing light means a misfire heavy enough to damage the catalytic converter.
Symptoms you might notice
- Shaking or a stumble, most noticeable at idle
- Hesitation or lost power under acceleration
- Check engine light that flashes when the misfire is heavy
What to check first
- Find cylinder 1 on your engine. Its location depends on the engine layout, so confirm it before you swap anything.
- Swap the ignition coil from cylinder 1 with the coil from another cylinder, clear the code, and drive. If the misfire code moves to the other cylinder, the coil is bad.
- If the code stays on cylinder 1, do the same swap with the spark plug.
- If both parts check out, look at the fuel injector for that cylinder, and only then consider a compression test.
Most common causes
- Bad ignition coil on cylinder 1
- Worn spark plug
- Failed fuel injector
- Low compression on that cylinder
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.