Quick Diagnosis Guide
Meaning: Code P0301 indicates that the vehicle's onboard computer (ECU) has registered a fault in the powertrain (p) circuits.
Can I still drive? No, running with a dead cylinder causes engine vibration and can destroy the catalyst.
What does the P0301 code mean?
Diagnostic Trouble Code (DTC) P0301 stands for Cylinder 1 Misfire Detected. This is a generic OBD-II trouble code indicating that the ECU has detected system performance parameters that fall outside normal calibrated tolerances.
When this code is logged, the ECU illuminates the dashboard check engine light and triggers a freeze frame record of engine sensor values to help diagnose the issue.
Common Symptoms of Code P0301
Depending on the vehicle make and driving conditions, you may observe the following symptoms:
- Engine hesitation
- Rough idling
- Vibrating dashboard and engine compartment
- Flashing Check Engine Light
What causes the P0301 fault code?
Root causes for a P0301 code typically include:
- Potential Cause 1: Faulty spark plug or coil on Cylinder 1
- Potential Cause 2: Bad fuel injector on Cylinder 1
- Potential Cause 3: Loss of engine compression on Cylinder 1 (valves/rings)
Repair Database Status
No verified vehicle-specific workshop fix is currently logged in our mobile mechanic database for this code. Refer to the diagnostic checklist below to isolate the fault.
Step-by-Step Diagnostic & Inspection Checklist
To inspect and troubleshoot a P0301 code, mechanics follow these validation steps:
- Step 1: Use OBDAssistant to verify the misfire is confined to Cylinder 1.
- Step 2: Swap Cylinder 1 ignition coil with Cylinder 2 and check if the code changes to P0302.
Estimated Repair Cost Band
$60 - $200 for a spark plug and ignition coil.
Note: Repair estimates vary based on vehicle make, model, local labor rates, and whether you require a full parts replacement.
Related Trouble Codes
If your scan tool registers other codes, check out these related guides:
Frequently Asked Questions
No, it is highly recommended to tow or park the vehicle to prevent costly catalytic converter damage.