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

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 before starting.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Unplug the electrical connector.
  • Remove the mounting bolts using a socket wrench.
• Extract the spark plug using a spark plug socket.
• Inspect the old spark plug for wear and replace with a new plug that meets OEM specifications.
• Reinstall the spark plug and tighten to the manufacturer’s torque specification (typically 13 lb-ft for Honda).

3. Test and Replace Ignition Coil (if needed)

• Use a multimeter to check the resistance of the ignition coil:
  • Compare readings with specifications from the service manual.
• If the coil is faulty, replace it:
  • Install the new ignition coil in cylinder 1 and secure it with bolts.
  • Reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Remove the fuel injector from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the fuel rail if necessary.
• Clean the injector using a dedicated injector cleaner or replace it if it shows signs of blockage or malfunction.
• Reinstall the fuel injector securely.

5. Perform Compression Test

• Ensure all spark plugs are removed.
• Insert the compression gauge into the cylinder 1 spark plug hole.
• Crank the engine several times and record the pressure reading.
• Compare to the manufacturer’s specifications (typically around 180 psi for Honda).

6. Reassemble and Test

• Reinstall any removed components, ensuring all connections are secure.
• Reconnect the battery terminal.
• Start the engine and check for smooth operation.