how to fix P0302 misfire code in BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical shorts.
• Allow the engine to cool down if it was recently running.

2. Replace Spark Plug (if faulty)

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 2 by unbolting it and disconnecting the electrical connector.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear; replace if necessary.
• Install the new spark plug and torque it to the manufacturer’s specification (typically around 20 Nm).
• Reinstall the ignition coil, ensuring the connector is secure.

3. Replace Ignition Coil (if faulty)

• If the ignition coil for cylinder 2 was found faulty during inspection, remove it as described above.
• Install the new ignition coil, ensuring it is properly seated and the connector is securely attached.

4. Test Fuel Injector (if necessary)

• If the fuel injector is suspected to be faulty, remove the fuel rail to access the injector for cylinder 2.
• Replace the injector if it fails the operation test.
• Reinstall the fuel rail and ensure all connections are secure.

5. Final Checks

• Reconnect the battery and clear the error codes using the OBD-II scanner.
• Start the engine and monitor for any new or recurring codes.