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

Solution

1. Preparation

• Gather tools and parts. Ensure the vehicle is parked on a level surface, and the engine is cool.
• Tools Required:
  • OBD-II scanner
  • Socket set
  • Torque wrench
  • Compression tester
  • Noid light or multimeter
  • Screwdrivers
  • Pliers

2. Inspect and Replace Spark Plug

• Remove the engine cover (if applicable) to access the spark plug.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 1.
• Using a spark plug socket, remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug (OEM recommended) and torque to the manufacturer’s specification (typically around 22 ft-lbs).

3. Check and Replace Ignition Coil

• Inspect the ignition coil for cracks or signs of overheating.
• If damaged, remove the ignition coil and replace it with a new one (OEM recommended).
• Reinstall the ignition coil and reconnect the electrical connector.

4. Test Fuel Injector

• Disconnect the fuel injector connector.
• Use a noid light or multimeter to check for proper signal to the injector.
• If no signal is detected, further inspect wiring or replace the injector if necessary.
• If the injector is faulty, remove it using appropriate tools and replace it with a new one.

5. Compression Test

• If misfire persists, perform a compression test on cylinder 1.
• Remove the spark plug and insert the compression tester.
• Crank the engine and record the compression reading. It should be within the manufacturer’s specification (usually 150-200 psi).
• If the compression is low, further diagnosis is needed for potential internal engine issues.