how to fix P0303 misfire code in Honda Accord Eleventh Generation (2023-present)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Ensure the engine is cool and disconnect the negative battery terminal.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if necessary.
• Disconnect the electrical connector from the ignition coil on cylinder 3.
• Remove the ignition coil by unbolting it and pulling it out.
• Use the spark plug socket to remove the spark plug from cylinder 3.
• Inspect the spark plug for wear. If necessary, replace it with a new one, ensuring the gap is set according to manufacturer specifications (usually around 0.043 inches).
• Reinstall the spark plug and torque it to the specified value (typically around 13 lb-ft).

3. Replace Ignition Coil

• Reinstall the ignition coil onto the new spark plug.
• Ensure that it is seated correctly and reconnect the electrical connector.
• If the ignition coil shows signs of failure (e.g., cracks, corrosion), replace it with a new one.
• Secure the ignition coil with the mounting bolts.

4. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Injector puller tool, fuel line disconnect tool.
• Disconnect the fuel line and electrical connector from the fuel injector for cylinder 3.
• Remove the retaining clips and pull out the injector using the injector puller tool.
• Inspect the injector for clogs; if it is not functioning properly, replace it with a new injector.
• Install the new injector and reconnect the fuel line and electrical connector.

5. Final Steps

• Reconnect the negative battery terminal.
• Start the engine and check for smooth operation.
• Clear any stored trouble codes with the OBD-II scanner.