how to fix P0301 misfire code in my BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shock.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug from cylinder 1.
• Inspect the old spark plug for wear and replace with a new spark plug, ensuring it is gapped correctly according to manufacturer specifications (typically around 0.025-0.032 inches).
• Torque the new spark plug to the manufacturer’s specification (usually around 18-20 ft-lbs).

3. Replace Ignition Coil

• Remove the ignition coil from cylinder 1 by unbolting it and disconnecting the electrical connector.
• Install a new ignition coil, ensuring it is properly seated and reattach the electrical connector.
• If you swapped ignition coils during diagnostics, ensure to return the swapped coil to its original cylinder.

4. Clean or Replace Fuel Injector

• Disconnect the fuel line and electrical connector from the fuel injector.
• Remove the fuel injector from cylinder 1. If cleaning, use a suitable injector cleaner.
• If replacing, install the new fuel injector, ensuring proper orientation and fit.

5. Reassemble and Test

• Reattach any components removed for access, including the engine cover.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach normal operating temperature.