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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before working.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the engine cover (if applicable) to access the spark plug.
• Carefully unscrew the old spark plug from cylinder 2 using the spark plug socket.
• Inspect the old spark plug for wear or deposits. Replace if it is fouled or damaged.
• Install the new spark plug and torque it to the manufacturer's specification (typically around 22 Nm or 16 lb-ft).
• Reattach the ignition coil to the spark plug.

3. Replace Ignition Coil

• Tools Required: Ratchet and socket set.
• Disconnect the electrical connector from the ignition coil.
• Remove the ignition coil from cylinder 2 by unscrewing the retaining bolts.
• Install the new ignition coil and secure it with the bolts. Reconnect the electrical connector.

4. Inspect/Replace Fuel Injector

• Tools Required: Fuel injector puller (if necessary), ratchet set.
• Disconnect the fuel injector connector.
• Remove the fuel rail (if necessary) to access the injector for cylinder 2.
• Inspect the fuel injector for clogs or damage. Replace if necessary.
• Reinstall the fuel rail and reconnect all connectors.

5. Compression Test (if needed)

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 2.
• Insert the compression tester and crank the engine to get a reading.
• Compare the compression value to the manufacturer's specifications. If low, further investigation is needed.