how to address the P0300 code on my Toyota Highlander Third Generation (2014-2019)?

Solution

1. Preparation

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

2. Inspect and Replace Spark Plugs

1. Remove the ignition coil covers if necessary.
2. Remove spark plugs using a spark plug socket and ratchet.
   • Tools Required: Spark plug socket, ratchet, extension.
3. Inspect spark plugs for wear (e.g., electrode wear, carbon buildup).
4. Replace with new spark plugs if necessary.
   • Torque Specification: 13 lb-ft (18 Nm) for spark plugs.

3. Inspect and Replace Ignition Coils

1. Remove the ignition coils by unscrewing the mounting bolts and disconnecting the electrical connectors.
2. Test each ignition coil with a multimeter for proper resistance.
3. Replace any faulty ignition coils with new ones.
   • Tools Required: Ratchet, socket set.
   • Torque Specification: 7 lb-ft (10 Nm) for ignition coil bolts.

4. Check Fuel Delivery

1. Connect a fuel pressure gauge to the fuel rail.
2. Turn the ignition to the "ON" position without starting the engine to check pressure.
3. Compare the reading with manufacturer specifications; replace the fuel filter if pressure is low.
   • Tools Required: Fuel pressure gauge.

5. Inspect and Repair Vacuum Leaks

1. Inspect vacuum hoses for cracks or disconnections.
2. Use a smoke machine or carburetor cleaner to find leaks around gaskets and hoses.
3. Replace any damaged hoses or gaskets found.