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

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3 using a socket set.
• Extract the spark plug using a spark plug socket.
• Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug, tightening to the manufacturer’s torque specification (typically 13-15 lb-ft).
• Reinstall the ignition coil onto the spark plug.

3. Inspect and Replace Ignition Coil

• If the spark plug is not the issue, replace the ignition coil for cylinder 3.
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil using a socket set.
• Install the new ignition coil and reconnect the electrical connector.

4. Test Fuel Injector

• If the coil replacement does not solve the issue, test the injector for cylinder 3.
• Disconnect the fuel injector connector.
• Use a noid light to check for signal; replace the injector if no signal is detected.
• If signal is present, check the injector for clogs by removing and testing it with a fuel pressure gauge.

5. Final Assembly and Testing

• Reconnect the battery terminal.
• Start the engine and allow it to reach operating temperature.
• Monitor for any check engine light or misfire symptoms.