how to fix engine misfire in my BMW 3 Series G20/G21 (2019-2024) with P0302 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool before starting.
• Disconnect the negative battery cable to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the engine cover if applicable.
• Locate the spark plug for cylinder 2.
• Use a spark plug socket and ratchet to remove the spark plug.
• Inspect the spark plug for signs of wear or fouling; replace with a new spark plug if necessary.
• Install the new spark plug and torque it to the manufacturer’s specifications (typically around 13-20 lb-ft).

3. Check and Replace Ignition Coil

• Disconnect the ignition coil connector for cylinder 2.
• Remove the ignition coil using a socket or ratchet.
• Inspect for cracks or damage; if faulty, replace the ignition coil with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Use a multimeter to test for proper resistance and functionality. Replace if faulty.
• Reinstall the fuel injector and reconnect the electrical connector.

5. Conduct Compression Test

• Remove the spark plug from cylinder 2 and insert a compression gauge.
• Crank the engine and record the compression reading. Compare it to the manufacturer's specifications.
• If the compression is low, further investigation into valve or piston issues is required.