how to address the P0300 code in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool completely before proceeding.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, spark plug socket, torque wrench.
• Remove the ignition coil cover if applicable.
• Disconnect the electrical connector from each ignition coil.
• Remove the ignition coils using a socket.
• Use a spark plug socket to remove the spark plugs.
• Inspect the spark plugs for wear and replace them if necessary.
• Install new spark plugs, torquing them to the manufacturer's specifications (typically around 13-15 lb-ft).
• Reinstall the ignition coils and connect the electrical connectors.

3. Inspect and Replace Ignition Coils

• Tools Required: Socket set, torque wrench.
• If any ignition coils were found defective, replace them by removing the old coils using a socket.
• Install the new ignition coils and ensure they are properly seated.
• Torque the ignition coils to the specified value (typically around 7-10 lb-ft).

4. Test Fuel Injectors

• Tools Required: Fuel pressure gauge, multimeter.
• Connect the fuel pressure gauge to the fuel rail to check for proper fuel pressure.
• If pressure is low, check the fuel pump and filter for issues.
• Use a multimeter to check the resistance of each fuel injector. Replace any that are out of spec.

5. Inspect Air Intake and Vacuum Leaks

• Visually inspect the air intake system for any cracks or loose connections.
• Use a smoke machine or carburetor cleaner to check for vacuum leaks around hoses and gaskets.
• Repair or replace any damaged parts found during the inspection.