how to fix P0302 misfire code on BMW X3 F25 (2011-2018)

Solution

1. Preparation

• Gather tools and required parts.
• Ensure the engine is cool, and disconnect the negative battery terminal.

2. Replace Spark Plug

1. Remove the ignition coil from cylinder 2:
   • Unplug the electrical connector from the ignition coil.
   • Remove the bolts securing the ignition coil using a socket set.
   • Carefully pull out the ignition coil.
2. Remove the spark plug:
   • Use a spark plug socket to unscrew and remove the spark plug from cylinder 2.
3. Install the new spark plug:
   • Apply a small amount of anti-seize compound to the threads of the new spark plug (if recommended).
   • Hand-tighten the spark plug, then use a torque wrench to tighten it to the manufacturer's specified torque (typically around 18-25 Nm).
4. Reinstall the ignition coil:
   • Place the ignition coil back into the spark plug well.
   • Secure it with bolts and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

1. If the ignition coil was found defective during inspection:
   • Follow the steps above to remove the faulty coil.
   • Install the new ignition coil as per the previous instructions.

4. Test Fuel Injector

1. If the spark plug and ignition coil are functioning properly:
   • Use a multimeter to check the resistance of the fuel injector for cylinder 2.
   • If the resistance is outside the manufacturer's specifications, replace the fuel injector.
2. If no issues are found, perform a fuel injector cleaning.

5. Clear Codes and Test Drive

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0302 code.
3. Start the engine and check for any signs of misfire.
4. Take the vehicle for a test drive to ensure the issue is resolved.