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

Solution

1. Preparation

• Gather all required tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Unplug the electrical connector and remove the retaining bolt.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for signs of wear or damage (burnt, cracked, or carbon-fouled).
• Replace the spark plug with a new one that meets OEM specifications (e.g., NGK or Bosch).
• Reinstall the ignition coil, ensuring it is seated properly and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil

• If the spark plug appears fine, test the ignition coil:
  • Swap the ignition coil from cylinder 1 with another cylinder (e.g., cylinder 2) and clear the codes.
  • If the P0301 code moves to the new cylinder, replace the ignition coil with a new OEM part.
• If replacing, ensure the new ignition coil is compatible with the vehicle’s specifications.

4. Check and Clean Fuel Injector

• If misfire persists, check the fuel injector:
  • Remove the fuel injector connector and inspect for damage.
  • Test the injector's resistance with a multimeter (specifications typically around 12-16 ohms for most fuel injectors).
• If faulty, replace the fuel injector with a new OEM part.
• Clean the injector ports and ensure proper seating when reinstalling.

5. Verify and Reassemble

• Reconnect all electrical connectors and ensure all components are securely reassembled.
• Reconnect the vehicle battery.
• Start the engine and allow it to idle to ensure the misfire code is resolved.