how to fix Honda Civic 9th Generation (2012-2015) check engine light P0301

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool if it has been running.

2. Inspect and Replace Spark Plug

• Remove the spark plug cover, if applicable.
• Use a spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or fouling; replace if necessary.
• Install a new spark plug (OEM recommended) and torque to manufacturer specifications (typically around 13-16 lb-ft).

3. Test and Replace Ignition Coil

• Disconnect the ignition coil connector from cylinder 1.
• Remove the ignition coil using a socket wrench.
• Test the ignition coil with a multimeter (check resistance; reference service manual for specific values).
• If the coil is faulty, replace it with a new one; torque the mounting bolt to specification.
• Reconnect the ignition coil connector.

4. Check and Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Remove the fuel rail if necessary to access the injector.
• Inspect the injector for clogs or damage; perform a bench test if possible.
• Replace with a new fuel injector if malfunctioning, ensuring proper sealing.
• Reassemble the fuel rail and reconnect any lines.

5. Verify Repair

• Reconnect the negative battery terminal.
• Start the engine and let it idle; monitor for any warning lights.
• Perform a test drive to ensure the check engine light does not return.