how to fix P0301 misfire code on BMW 5 Series G30/G31 (2017-2024)

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Gather necessary tools and parts.

2. Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector for cylinder 1.
• Remove the ignition coil bolt and gently pull the ignition coil out.
• Using a spark plug socket, carefully unscrew the spark plug from cylinder 1.
• Inspect the spark plug and replace it with a new one, ensuring the gap is set to the manufacturer’s specifications (typically around 0.028-0.032 inches).
• Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil

• Tools Required: Socket set, torque wrench
• If the ignition coil shows signs of damage during inspection, replace it.
• Remove the old ignition coil as described above.
• Install the new ignition coil and ensure it is seated properly.
• Torque the ignition coil bolt to the manufacturer’s specifications (consult service manual for exact torque value).

4. Fuel Injector Inspection and Replacement (if necessary)

• Tools Required: Fuel injector puller, socket set, torque wrench
• If the fuel injector was found to be faulty during testing, remove it:
  • Disconnect the fuel line and the electrical connector from the injector.
  • Remove any clips or bolts securing the injector.
  • Pull the injector out carefully.
• Replace with a new fuel injector, ensuring it is properly seated and secured.
• Reconnect the fuel line and electrical connector.

5. Reassemble and Reconnect

• Reattach the engine cover if it was removed.
• Reconnect the negative battery terminal.