how to fix P0301 misfire code on BMW 3 Series G20/G21 (2019-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid any electrical issues during repair.

2. Replace Spark Plug

• Tools Required: Socket set, spark plug gap tool, torque wrench.
• Remove the engine cover if necessary.
• Disconnect the ignition coil connector.
• Remove the ignition coil from cylinder 1.
• Unscrew the spark plug using a spark plug socket.
• Inspect the old spark plug for wear; replace if necessary.
• Install the new spark plug, ensuring the gap is set to manufacturer specifications (typically around 0.028-0.032 inches).
• Torque the spark plug to the manufacturer’s specification (usually around 18-22 lb-ft).
• Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil was found defective during diagnostics, replace it.
• Tools Required: Socket set.
• Remove the ignition coil as described in the previous step.
• Install the new ignition coil in place, ensuring it's seated properly.
• Reconnect the ignition coil connector.

4. Inspect and Clean Fuel Injector (if necessary)

• If the fuel injector was suspected to be faulty, remove and clean or replace it.
• Tools Required: Fuel injector removal tool, cleaning solvent.
• Disconnect the fuel line and electrical connector from the injector.
• Remove the fuel injector using the removal tool.
• Clean the injector with appropriate solvent (or replace if necessary) and reinstall.

5. Final Assembly

• Reinstall any engine covers or components removed during the repair.
• Reconnect the battery.