how to solve the P0301 misfire code in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

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

2. Spark Plug Replacement

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 1:
  • Unplug the electrical connector.
  • Remove the bolts securing the ignition coil and carefully lift it out.
• Remove the spark plug:
  • Use the spark plug socket to unscrew and remove the old spark plug.
• Install the new spark plug:
  • Apply anti-seize compound to the threads (if recommended).
  • Hand-tighten the spark plug and then torque it to the manufacturer's specification (usually around 13-15 lb-ft).
• Reinstall the ignition coil:
  • Position the coil over the spark plug, secure it with bolts, and reconnect the electrical connector.

3. Fuel Injector Inspection and Replacement (if needed)

• Tools Required: Fuel injector puller, socket set, torque wrench
• Remove the fuel rail assembly to access the fuel injector for cylinder 1:
  • Disconnect fuel lines and electrical connectors from the fuel rail.
  • Remove the bolts securing the fuel rail and gently lift it.
• Inspect the fuel injector for any blockages or damage:
  • If faulty, remove the injector using the fuel injector puller.
• Install the new fuel injector:
  • Lubricate the O-ring on the new injector with engine oil and insert it into the rail.
  • Reinstall the fuel rail, ensuring all connections are secure and properly torqued.

4. Final Assembly

• Reconnect the negative battery terminal.
• Start the engine and check for smooth operation and no misfire codes.