how to fix P0301 misfire code on my BMW X5 F15 (2014-2019)?

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the negative terminal of the battery.
• Allow the engine to cool before starting work.

2. Inspect and Replace the Spark Plug

• Remove the engine cover (if applicable) using a socket wrench.
• Disconnect the ignition coil connector for cylinder 1.
• Remove the ignition coil using a socket wrench.
• Unscrew the spark plug using a spark plug socket.
• Inspect the spark plug for wear; replace if fouled or worn.
• Install a new spark plug (torque to 22 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace the Ignition Coil

• If the spark plug is in good condition but the code persists, proceed to check the ignition coil.
• Remove the ignition coil for cylinder 1 as described in the previous step.
• Replace it with a new ignition coil.
• Ensure it is seated properly and reconnect the electrical connector.

4. Check Fuel Injector

• If the misfire continues, check the fuel injector for cylinder 1:
  • Disconnect the fuel injector connector.
  • Remove the fuel rail if necessary to access the injector.
  • Inspect the injector for clogs or damage.
  • Replace with a new injector if faulty.
  • Reassemble the fuel rail and reconnect the injector connector.

5. Compression Test

• If the issue still persists, perform a compression test:
  • Remove the spark plug for cylinder 1.
  • Insert the compression gauge into the cylinder.
  • Crank the engine to get a reading.
  • Compare the reading to the manufacturer’s specifications (ideally 140-200 psi).
  • If compression is low, further investigation into engine internals is necessary.