how to diagnose P0302 misfire code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 2:
  • Remove the bolt securing the ignition coil.
  • Carefully disconnect the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for damage; replace if necessary.
• Install a new spark plug, tightening to the manufacturer's specified torque (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• If the misfire is still present, test the ignition coil:
  • Swap the ignition coil with one from a different cylinder.
  • Clear the DTCs and perform a test drive to see if the P0302 code reappears.
• If the code reappears for cylinder 2, replace the ignition coil with a new one, and ensure it is seated properly.

4. Check and Replace Fuel Injector (if necessary)

• If the misfire persists, check the fuel injector for cylinder 2:
  • Remove the fuel rail assembly according to manufacturer guidelines.
  • Inspect the injector for clogs or leaks.
• Replace the fuel injector if it is found to be faulty, ensuring to use quality replacement parts.

5. Reassemble and Reconnect Battery

• Ensure all components are installed correctly.
• Reconnect the negative battery terminal.
• Start the engine and monitor for any warning lights.