my BMW 3 Series F30/F31 (2012-2019) has a check engine light with P0301 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the engine cover if applicable.
• Locate cylinder 1 spark plug (usually at the front of the engine).
• Use a spark plug socket to remove the old spark plug.
• Inspect the old spark plug for signs of fouling or damage.
• Install the new spark plug, ensuring it is torqued to the manufacturer's specifications (typically around 13 lb-ft).

3. Replace Ignition Coil

• Tools Required: Socket set
• Remove the ignition coil for cylinder 1 by unscrewing the mounting bolts.
• Disconnect the electrical connector from the ignition coil.
• Install the new ignition coil in place and reconnect the electrical connector.
• Secure the ignition coil with the mounting bolts.

4. Inspect and Clean Fuel Injector (if necessary)

• Tools Required: Fuel injector cleaning kit (if cleaning is needed)
• Disconnect the fuel line and electrical connector from the injector.
• Remove the injector using appropriate tools.
• Clean the injector using a fuel injector cleaning kit or replace it with a new one if it is faulty.
• Reinstall the injector and reconnect the fuel line and electrical connector.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0301 code from the ECU.