What does OBD2 code P0301 mean?
The engine control module (ECM) or powertrain control module (PCM) sets code P0301 when it registers that the Cylinder 1 Misfire Detected performance has fallen below the manufacturer's required baseline. This triggers your vehicle's malfunction indicator lamp (MIL), commonly known as the Check Engine Light.
Is It Safe to Drive with Code P0301?
No, running with a dead cylinder causes engine vibration and can destroy the catalyst.
Symptoms of OBD2 Code P0301
Depending on your car model, symptoms for P0301 may vary. The most typical symptoms include:
- Engine hesitation
- Rough idling
- Vibrating dashboard and engine compartment
- Flashing Check Engine Light
What Causes Code P0301?
A variety of physical faults can trigger the P0301 code. Here are the most frequent culprits:
- Faulty spark plug or coil on Cylinder 1
- Bad fuel injector on Cylinder 1
- Loss of engine compression on Cylinder 1 (valves/rings)
Step-by-Step Diagnostic Routine
Before replacing any expensive components, run through these standardized troubleshooting steps:
- Use OBDAssistant to verify the misfire is confined to Cylinder 1.
- Swap Cylinder 1 ignition coil with Cylinder 2 and check if the code changes to P0302.
Expected Repair Costs for P0301
$60 - $200 for a spark plug and ignition coil.
Save on Diagnosis with OBDAssistant
OBDAssistant guides you through coil swapping diagnostics to pinpoint bad coils without buying parts unnecessarily.
Frequently Asked Questions
No, it is highly recommended to tow or park the vehicle to prevent costly catalytic converter damage.