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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the engine to cool completely before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, anti-seize compound.
• Remove the engine cover if necessary.
• Use the socket to remove the spark plug from cylinder 1.
• Inspect the old spark plug for wear; if damaged, replace it with a new spark plug.
• Apply a small amount of anti-seize compound to the threads of the new spark plug.
• Install the new spark plug and torque it to the manufacturer’s specification (usually around 18-22 Nm).
• Reinstall the engine cover.

3. Replace Ignition Coil

• Tools Required: Socket set.
• Disconnect the wiring harness from the ignition coil in cylinder 1.
• Remove the bolts securing the ignition coil and take it out.
• Install the new ignition coil and secure it with bolts.
• Reconnect the wiring harness.

4. Check Fuel Injector

• Tools Required: Fuel pressure gauge, injector cleaner.
• Inspect the fuel injector for any clogs or leaks.
• If clogged, consider using fuel injector cleaner.
• If damage is found, replace the fuel injector with a new one.

5. Verify Electrical Connections

• Tools Required: Multimeter.
• Check the wiring and connectors for the ignition coil and fuel injector for continuity and damage.
• Repair or replace any damaged wiring or connectors as necessary.