how to fix the P0300 misfire code on my BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Park the vehicle on a flat surface and engage the parking brake.
• Disconnect the battery negative terminal to prevent any electrical shorts.

2. Inspect and Replace Spark Plugs

• Remove the engine cover (if applicable) using the appropriate socket.
• Disconnect the ignition coil connectors and remove the ignition coils using a socket set.
• Remove the spark plugs using a spark plug socket. Inspect for wear or damage.
• Install new spark plugs (specify gap according to manufacturer specifications) and torque to 22 ft-lbs.
• Reinstall the ignition coils and reconnect the connectors.

3. Test and Replace Ignition Coils (if necessary)

• If the ignition coils were found faulty during diagnostics, replace them as follows:
  • Remove the old coils as described above.
  • Install new ignition coils and ensure all connectors are secure.
  • Reconnect the battery negative terminal.

4. Check and Replace Fuel Injectors (if necessary)

• If fuel injectors are suspected, remove the intake manifold for access.
• Disconnect the fuel lines and electrical connectors from the injectors.
• Remove the faulty injectors and install new ones, ensuring O-rings are lubricated and seated correctly.
• Reassemble the intake manifold and reconnect all components securely.

5. Verify and Test

• Start the engine and allow it to reach operating temperature.
• Use an OBD-II scanner to clear the P0300 code and monitor for any reoccurrence.
• Test drive the vehicle to ensure proper performance.