my Honda Civic 11th Generation (2022-Present) has a P0304 code, what does that mean?

Learn how to diagnose and fix P0304 cylinder 4 misfire in Honda Civic 11th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 4 by unscrewing the mounting bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for signs of wear or damage; replace it if necessary.
• Install the new spark plug to the manufacturer’s torque specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil was found to be faulty during diagnostics, remove it from cylinder 4.
• Install a new ignition coil by securing it in place and reconnecting the electrical connector.
• Repeat the same for any additional cylinders if multiple misfires are detected.

4. Test Fuel Injector

• Remove the fuel injector from cylinder 4 by disconnecting the electrical connector and unscrewing any mounting bolts.
• Use a fuel injector tester to verify proper operation, or replace with a new injector if it is defective.
• Reinstall the fuel injector and reconnect all electrical connections.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the trouble codes and reset the check engine light.