how to fix P0301 misfire code on Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Gather tools and parts needed.
• Tools Required: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, multimeter, compression tester, noid light.
• Park the vehicle on a level surface and ensure the engine is cool before starting repairs.

2. Inspect and Replace Spark Plug

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coil connector for cylinder 1.
• Remove the ignition coil using a socket set.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or damage. Replace it if necessary.
  • Recommended spark plug gap: 0.044 inches (1.1 mm).
• Reinstall the new spark plug and torque to manufacturer specifications (usually around 13 lb-ft).

3. Check and Replace Ignition Coil

• If the spark plug is fine, test the ignition coil using a multimeter for primary and secondary resistance.
• If it is out of specification, replace the ignition coil for cylinder 1.
• Reinstall the ignition coil and reconnect the connector.

4. Inspect and Replace Fuel Injector

• If the ignition system is functioning properly, check the fuel injector for cylinder 1.
• Remove the fuel rail as per the service manual instructions (ensure to relieve fuel pressure before removal).
• Inspect the fuel injector O-rings for damage. Replace the injector if it is clogged or malfunctioning.
• Reinstall the fuel injector and torque the fuel rail to specifications.

5. Reassemble and Clear Codes

• Reinstall any components removed, including the engine cover.
• Reconnect the battery (if disconnected).
• Use the OBD-II scanner to clear the P0301 code.