how to fix P0301 misfire code in BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

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

2. Inspect and Replace Ignition Coil

• Tools Required: Socket set, ratchet, torque wrench
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the electrical connector from the ignition coil for cylinder 1.
  3. Remove the bolt securing the ignition coil using a socket.
  4. Pull the ignition coil out of the spark plug well.
  5. Install the new ignition coil and secure it with the bolt. Torque to manufacturer specifications (usually around 10 Nm).
  6. Reconnect the electrical connector.

3. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench
• Sub-steps:
  1. Remove the ignition coil as described above.
  2. Use a spark plug socket to unscrew the old spark plug from cylinder 1.
  3. Inspect the old spark plug for wear or fouling.
  4. Gap the new spark plug according to manufacturer specifications.
  5. Install the new spark plug and torque to manufacturer specifications (usually around 25 Nm).
  6. Reinstall the ignition coil.

4. Test Fuel Injector

• Tools Required: Fuel injector tester
• Sub-steps:
  1. Disconnect the fuel injector harness for cylinder 1.
  2. Use a fuel injector tester to check the injector’s operation.
  3. If the injector fails the test, replace it with a new fuel injector.
  4. Reconnect the fuel injector harness.

5. Check Compression (if necessary)

• Tools Required: Compression tester
• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Screw in the compression tester.
  3. Crank the engine several times to get a reading.
  4. Compare the compression reading to manufacturer specifications. If low, investigate potential causes such as valve issues or head gasket failure.