how to fix P0302 misfire code on my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

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

2. Replace Spark Plug and Ignition Coil (if necessary)

• Tools Required: Socket set, torque wrench, ratchet, spark plug socket.
• Steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 2.
  3. Remove the bolts securing the ignition coil using the socket set.
  4. Gently pull the ignition coil out from the spark plug.
  5. Use the spark plug socket to remove the spark plug from cylinder 2.
  6. Inspect the old spark plug; if it appears worn or fouled, replace it with a new one.
  7. Install the new spark plug, torque it to the manufacturer's specification (typically around 13 lb-ft).
  8. Reinstall the ignition coil, securing it with bolts, and reconnect the ignition coil connector.

3. Test Fuel Injector Operation

• Tools Required: Fuel injector cleaner, multimeter (optional).
• Steps:
  1. Disconnect the fuel injector connector for cylinder 2.
  2. Use a multimeter to check for proper voltage at the connector (if applicable).
  3. If no voltage is detected, trace back to the ECU for further diagnostics.
  4. If voltage is present, consider cleaning the injector using a fuel injector cleaner or replacing the injector if necessary.

4. Compression Test

• Tools Required: Compression gauge.
• Steps:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression gauge into the spark plug hole.
  3. Crank the engine for about 5-7 seconds to get a reading.
  4. Compare the reading to manufacturer specifications (typically around 180-220 psi).
  5. If compression is low, further investigation into engine internals may be necessary.