how to fix P0304 code in Honda Accord 8th Generation (2008-2012)

Learn how to diagnose and fix P0304 cylinder 4 misfire in Honda Accord 2008-2012. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and necessary parts.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 4:
  • Use a socket set to unscrew the mounting bolts.
  • Gently pull the coil out.
• Remove the spark plug from cylinder 4:
  • Use a spark plug socket to unscrew and remove the spark plug.
• Install a new spark plug:
  • Ensure gap is set to manufacturer specifications (typically around 0.043 inches for Honda).
  • Torque to specification (around 13 lb-ft).

3. Replace Ignition Coil (if necessary)

• If the ignition coil is found faulty:
  • Install the new ignition coil in cylinder 4.
  • Ensure it is seated properly and tighten the mounting bolts to the specified torque.

4. Inspect and Replace Fuel Injector (if necessary)

• If the fuel injector is suspected to be faulty:
  • Remove the fuel rail by unscrewing the bolts.
  • Disconnect the fuel line carefully.
  • Replace the faulty fuel injector with a new one.
  • Reassemble the fuel rail and ensure all connections are secure.

5. Clear Codes and Reconnect Battery

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear any stored codes.