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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil cover (if applicable).
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil from cylinder 1.
• Use a spark plug socket to remove the spark plug from cylinder 1.
• Inspect the spark plug's condition. Replace with a new spark plug if damaged or worn.
• Install the new spark plug and torque to manufacturer specifications (typically around 18 ft-lbs).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil

• Tools Required: Socket set, multimeter (optional)
• If the spark plug is in good condition, test the ignition coil using a multimeter for proper resistance.
• If the coil is faulty, replace it with a new ignition coil for cylinder 1.
• Ensure all connections are secure after installation.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, fuel line disconnect tool (if needed)
• If the ignition components are functioning correctly, test the fuel injector for cylinder 1.
• Remove the fuel injector from cylinder 1.
• Clean the injector with fuel injector cleaner or replace it if it shows signs of clogging.
• Reinstall the fuel injector and ensure proper sealing.

5. Compression Test

• Tools Required: Compression tester
• If misfire persists, perform a compression test on cylinder 1.
• Compare the reading to manufacturer specifications (usually 120-200 psi).
• If compression is low, further diagnostics may be needed for possible internal engine issues.