how to fix P0300 code in Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool before beginning work.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug boots.
• Extract the spark plugs with a spark plug socket.
  • Tools Required: Spark plug socket, ratchet, torque wrench.
  • Safety Warning: Ensure the engine is cool to avoid burns.
• Inspect the spark plugs for wear, carbon buildup, or damage.
• Replace spark plugs with OEM or high-quality aftermarket plugs, ensuring the correct gap is set.
• Torque the new spark plugs to manufacturer specifications (typically around 13-15 ft-lbs).

3. Check and Replace Ignition Coils

• Remove the ignition coil connectors.
• Unscrew the ignition coils with a socket wrench.
• Test each ignition coil with a multimeter (should read within specified resistance).
• Replace any faulty ignition coils with new ones (OEM recommended).
• Reinstall the ignition coils and reconnect the connectors.

4. Inspect Fuel Injectors

• Remove the intake manifold if necessary to access fuel injectors.
• Inspect fuel injectors visually for any signs of leaks or carbon deposits.
• Clean or replace clogged fuel injectors as needed.
• Reassemble all components securely.

5. Verify Vacuum Lines

• Check all vacuum lines connected to the intake manifold for cracks or loose connections.
• Replace any damaged vacuum lines to ensure proper engine operation.