my BMW X3 G01 (2018-2024) has a check engine light and misfire code P0301, what's wrong?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug from cylinder 1.
  • Tools Required: Spark plug socket, ratchet, torque wrench
• Inspect the old spark plug for wear; replace if necessary.
• Install a new spark plug into cylinder 1, tightening it to the manufacturer's specified torque (typically 18-25 Nm).
• Reconnect the spark plug wire or coil.

3. Inspect and Replace Ignition Coil

• Remove the ignition coil from cylinder 1 by unscrewing any retaining screws.
• Inspect the coil for cracks or corrosion.
• If faulty, replace with a new ignition coil.
• Reinstall the ignition coil, ensuring secure connections.

4. Check Compression

• Remove the spark plug from cylinder 1 and attach the compression gauge.
• Crank the engine to obtain a compression reading.
• Compare the reading with manufacturer specifications (usually around 200 psi).
• If compression is low, further investigation into piston rings or valve issues is required.

5. Fuel Injector Inspection

• Remove the fuel rail to access the injector for cylinder 1.
• Check for clogs or leaks in the injector.
• If faulty, replace the fuel injector with a new one.
• Reinstall the fuel rail and ensure all connections are secure.