how to fix P0301 misfire code on Honda Civic 9th Generation (2012-2015)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work on it.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket, anti-seize compound.
• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts and disconnecting the electrical connector.
• Use a spark plug socket to remove the old spark plug.
• Inspect the spark plug for wear and replace it with a new one, applying a small amount of anti-seize compound to the threads.
• Torque the new spark plug to the manufacturer's specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test Ignition Coil

• If the spark plug replacement does not resolve the issue, test the ignition coil using a multimeter.
• Tools Required: Multimeter.
• Disconnect the ignition coil from the electrical connector.
• Set the multimeter to measure resistance and check the primary and secondary resistance as per manufacturer specifications.
• If the coil is faulty, replace it with a new one.

4. Inspect and Clean Fuel Injector

• If the ignition coil is functioning correctly, check the fuel injector for cylinder 1.
• Tools Required: Fuel injector cleaning kit, appropriate cleaning solvent.
• Disconnect the fuel injector electrical connector and remove it from the fuel rail.
• Clean the injector using a cleaning kit and solvent, or replace it if it is found to be faulty.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 1.
• Tools Required: Compression tester.
• Remove the spark plug and screw in the compression tester.
• Crank the engine and record the compression reading. Compare it with specifications (usually around 180 psi).
• If compression is low, further investigation into internal engine components may be required (valves, piston rings).