how to fix P0302 misfire code on BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Inspect and Replace Spark Plug

• Remove the engine cover if necessary.
• Locate the spark plug for cylinder 2 (refer to your engine's layout).
• Use a spark plug socket to remove the spark plug.
• Inspect the spark plug for wear or fouling.
• If damaged, replace it with a new spark plug, ensuring the gap is set to manufacturer specifications (usually around 0.030 inches for BMW).
• Reinstall the spark plug and torque it to the recommended specification (typically around 20 Nm).

3. Check and Replace Ignition Coil

• Disconnect the wiring harness from the ignition coil on cylinder 2.
• Remove the ignition coil by unscrewing any retaining bolts if applicable.
• Inspect the coil for cracks or damage; replace if necessary with a new coil.
• Reinstall the ignition coil and reconnect the wiring harness.

4. Inspect Fuel Injector

• Locate the fuel injector for cylinder 2.
• Disconnect the electrical connector and fuel line from the injector (be cautious of fuel spills).
• Remove the fuel injector from the rail.
• Inspect for clogs or damage; replace if necessary.
• Reinstall the new or cleaned injector, ensuring proper sealing.

5. Reassemble and Reset

• Reconnect any components or covers removed during the process.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach normal operating temperature.