how to fix P0304 code on 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 all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the ignition coil from cylinder 4 by disconnecting the electrical connector and unscrewing the mounting bolts.
• Extract the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear, fouling, or damage. Replace if necessary.
• Install the new spark plug, ensuring a torque of 13 lb-ft (18 Nm).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• Tools Required: Multimeter
• Use a multimeter to test the resistance of the ignition coil. Compare readings to manufacturer specifications.
• If the coil is faulty, remove it and replace it with a new one.
• Ensure proper connection and secure mounting.

4. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector removal tool, safety glasses
• Remove the fuel rail to access the fuel injector for cylinder 4.
• Inspect the injector for clogs or damage. If necessary, replace it with a new injector.
• Reinstall the fuel rail and ensure all connections are secure.

5. Repair Compression Issues (if necessary)

• If compression test results indicate low compression in cylinder 4, further investigation is needed.
• This may involve removing the cylinder head to inspect for valve damage or gasket failure.