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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent any electrical shorts.
• Allow the engine to cool down before working.

2. Replace Spark Plug

1. Remove the engine cover if applicable.
2. Disconnect the ignition coil connector for cylinder 1.
3. Unscrew the ignition coil using a socket wrench and remove it from the spark plug.
4. Use a spark plug socket to remove the old spark plug.
5. Inspect the new spark plug to ensure it is the correct type and gap size (typically around 0.028-0.032 inches for BMW).
6. Install the new spark plug and torque to the manufacturer's specifications (usually around 18-22 lb-ft).
7. Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil (if necessary)

1. If the ignition coil appears faulty, remove it as described in the previous step.
2. Install the new ignition coil, ensuring it is seated correctly.
3. Reconnect the ignition coil connector.

4. Inspect Fuel Injector

1. If the issue persists, remove the fuel injector from cylinder 1.
2. Check for clogs or damage to the injector.
3. Clean the injector with an appropriate cleaner or replace it if necessary.
4. Reinstall the fuel injector and connect any necessary wiring.

5. Check for Vacuum Leaks

1. Inspect hoses and connections around the intake manifold for cracks or disconnections.
2. Use a smoke machine or carburetor cleaner to locate any leaks.
3. Repair or replace any damaged hoses or gaskets.