how do I fix the P0301 misfire code on my BMW 3 Series F30/F31 (2012-2019)?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Locate the spark plug for cylinder 1.
  3. Use a spark plug socket to remove the spark plug.
  4. Inspect the spark plug for wear, fouling, or damage; replace it if necessary.
  5. Apply anti-seize lubricant to the threads of the new spark plug.
  6. Torque the new spark plug to the manufacturer’s specifications (usually around 22 Nm).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Disconnect the electrical connector from the ignition coil.
  2. Remove the ignition coil using a socket or wrench.
  3. Inspect the coil for cracks or carbon tracking; replace if defective.
  4. Install the new ignition coil and reconnect the electrical connector.
  5. Ensure the coil is properly seated and secured.

4. Check and Clean Fuel Injector

• Sub-steps:
  1. Disconnect the fuel injector connector.
  2. Remove the fuel rail to access the injector if necessary.
  3. Inspect the fuel injector for clogs or damage; clean using a fuel injector cleaner or replace if needed.
  4. Reinstall the fuel injector and ensure it is seated correctly.

5. Reassemble and Test

• Sub-steps:
  1. Reconnect any components removed during the procedure (engine cover, fuel rail).
  2. Reconnect the negative battery terminal.
  3. Start the engine and observe for any misfire occurrences or check engine light activation.