P0301 Nissan Altima
Cylinder 1 Misfire Detected · Powertrain Code · High · Repair: Easy
What is P0301?
Misfire detected in cylinder 1. Typically caused by a worn spark plug, bad ignition coil, faulty fuel injector, or low compression in that cylinder.
When the Nissan Altima triggers code P0301 (cylinder 1 misfire detected), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Nissan Altima.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Nissan Altima.
Common Causes on Nissan Altima
- Ignition coil failure on cylinder 1 on 2.0L MR20DD or 2.5L QR25DE
- Spark plug worn beyond service interval on high-mileage engine
- Fuel injector partially clogged from deposit buildup
- Low compression from piston ring wear on QR25DE
Symptoms
- Rough idle with noticeable engine vibration
- Engine shaking or vibration especially at idle
- Loss of power during acceleration
- Check engine light flashing (indicating catalytic converter damage risk)
- Poor fuel economy from unburned fuel
- Unburned fuel smell from exhaust
Notes for Nissan Altima
Nissan QR25DE engines may consume oil at high mileage; check plug condition for oil fouling signs.