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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical issues and ensure safety.

Tools Required:

• OBD-II scanner
• Spark plug socket
• Torque wrench
• Multimeter
• Compression tester
• Ratchet and socket set
• Screwdrivers

2. Replace Spark Plug

• Remove Engine Cover:

  • Unscrew bolts and gently lift off the engine cover.

• Remove Spark Plug:

  • Use the spark plug socket to carefully unscrew and remove the spark plug from cylinder 1.

• Install New Spark Plug:

  • Apply anti-seize compound to the threads of the new spark plug.
  • Install the new spark plug by hand to avoid cross-threading, then torque to manufacturer specifications (usually around 23 Nm).

3. Replace Ignition Coil

• Remove Ignition Coil:

  • Disconnect the ignition coil connector and remove the mounting bolts.
  • Gently pull the ignition coil out of the cylinder head.

• Install New Ignition Coil:

  • Insert the new ignition coil into the cylinder head and secure it with bolts.
  • Reconnect the ignition coil electrical connector.

4. Clean or Replace Fuel Injector

• Remove Fuel Injector:

  • Relieve fuel pressure by removing the fuel pump fuse and running the engine until it stalls.
  • Disconnect fuel lines and electrical connector from the injector. Remove the retaining clip and pull out the injector.

• Clean or Replace Injector:

  • If cleaning, use a fuel injector cleaning kit. If replacing, install a new injector, lubricating the O-rings with engine oil before installation.

5. Reassemble and Test

• Reinstall the engine cover.
• Reconnect the battery.
• Clear the DTCs using the OBD-II scanner.