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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent any electrical issues during the repair.
• Ensure the engine is cool before starting work.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if present.
  2. Locate the spark plug for cylinder 1 (refer to the owner's manual for specific location).
  3. Use a spark plug socket and ratchet to remove the old spark plug.
  4. Inspect the old spark plug for wear or carbon buildup.
  5. Gap the new spark plug according to manufacturer specifications.
  6. Install the new spark plug and torque it to the manufacturer’s specified torque value (typically around 20 Nm).

3. Replace Ignition Coil

• Sub-steps:
  1. Disconnect the electrical connector from the ignition coil.
  2. Remove the bolts securing the ignition coil and lift it out.
  3. Install the new ignition coil, ensuring it is seated properly.
  4. Reconnect the electrical connector securely.

4. Check and Clean Fuel Injector

• Sub-steps:
  1. Disconnect the fuel line and electrical connector from the fuel injector for cylinder 1.
  2. Remove the fuel injector using a suitable tool.
  3. Inspect the injector nozzle for clogs and clean if necessary using a fuel injector cleaner.
  4. Reinstall the cleaned or new injector, ensuring it is seated properly in the intake manifold.

5. Reassemble and Test

• Sub-steps:
  1. Reconnect any components removed during the process.
  2. Reconnect the battery.
  3. Start the engine and check for smooth operation without misfire codes.

Tools Required:

• OBD-II scanner
• Spark plug socket
• Ratchet and extension
• Torque wrench
• Fuel injector puller (if necessary)
• Cleaning supplies for injector

Parts Required:

• Spark plug (for cylinder 1)
• Ignition coil (for cylinder 1)
• Fuel injector (if necessary)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect battery before working on electrical systems.
• Allow engine to cool before opening any components to avoid burns.