how to fix P0300 misfire code on BMW X3 G01 (2018-2024)?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the work area is clean and organized.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug wires or ignition coils.
• Remove the spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; replace any that are worn or fouled.
  • Torque specifications: Typically between 18-22 ft-lbs for installation.
• Reinstall new spark plugs and reconnect ignition coils/wires.

3. Check and Replace Ignition Coils

• If misfires persist, inspect ignition coils for damage.
• Remove the ignition coils using a socket wrench.
• Replace faulty ignition coils with new ones.
• Reinstall the ignition coils and reconnect the wiring harness.

4. Fuel System Inspection

• Using a fuel pressure gauge, connect it to the fuel rail.
• Turn the ignition to the "On" position (do not start) and check fuel pressure; it should match manufacturer specifications.
• If pressure is low, replace the fuel pump or fuel filter as needed.

5. Vacuum System Check

• Inspect all vacuum lines for cracks or disconnections.
• Replace any damaged vacuum hoses.
• If necessary, perform a smoke test to find hidden leaks.

6. Compression Test (If Needed)

• Remove all spark plugs for a compression test.
• Insert the compression tester into the first cylinder, crank the engine, and record the reading.
• Repeat for all cylinders; readings should be within manufacturer specifications.
• If readings are low, further engine diagnostics will be necessary.