how to resolve P0302 misfire code on Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and components.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the engine to cool before proceeding.

2. Replace Spark Plug on Cylinder 2

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 2.
  • Sub-step: Unscrew the retaining bolt and lift the coil out.
• Remove the spark plug using a spark plug socket.
  • Sub-step: Inspect the old spark plug for wear and carbon build-up.
• Install the new spark plug.
  • Sub-step: Torque the new spark plug to the manufacturer's specification (typically around 13-15 lb-ft).
• Reinstall the ignition coil.

3. Replace Ignition Coil (if necessary)

• Tools Required: Socket set, torque wrench.
• Remove the ignition coil from cylinder 2 as previously done.
• Install the new ignition coil.
  • Sub-step: Torque to manufacturer specifications (usually around 80-100 in-lbs).
• Reconnect the electrical connector securely.

4. Test Fuel Injector on Cylinder 2

• Tools Required: Fuel injector tester or multimeter.
• Disconnect the fuel injector connector for cylinder 2.
• Use the fuel injector tester to check for proper operation.
  • Sub-step: If the injector is faulty, replace it with a new one.
• Reconnect the fuel injector connector.

5. Perform Compression Test (if misfire persists)

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 2.
• Insert the compression tester and crank the engine.
• Compare the compression readings to manufacturer specifications.
  • Sub-step: If compression is low, further investigation into engine internals may be required.