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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent any electrical short circuits.
• Ensure the engine is cool before beginning work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil for cylinder 1 by unscrewing the retaining bolts and disconnecting the electrical connector.
• Extract the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for signs of wear or fouling. Replace it if necessary with a new OEM or equivalent spark plug.
• Torque the new spark plug to the manufacturer's specifications (typically around 22 Nm or 16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil

• If the spark plug was not the issue, remove the ignition coil from cylinder 1.
• Test the ignition coil with a multimeter to check its resistance. Replace it if it is out of specification.
• Install the new ignition coil, ensuring it is seated properly and secure it with the retaining bolts.

4. Inspect and Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to check for proper resistance of the fuel injector.
• If the injector is faulty, remove it using a fuel injector puller and replace it with a new one.
• Reconnect the fuel injector connector after installation.

5. Check Compression

• If misfire persists, perform a compression test on cylinder 1.
• If the compression is low, further investigation is needed, potentially involving a cylinder leak-down test to diagnose internal engine issues.