how to fix the check engine light on my Toyota Highlander Fourth Generation (2020-present) when I ha...

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety.
• Tools required: OBD-II scanner, socket set, screwdrivers, multimeter, fuel pressure gauge, and cleaning supplies.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect all vacuum hoses and connections for cracks or disconnections.
  • If any leaks are found, replace the damaged hoses or reconnect the dislocated parts.
  • Check the air filter; if dirty, replace it to ensure proper airflow.

3. Clean and Test MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake duct.
  • Use a MAF sensor cleaner to gently clean the sensor.
  • Reinstall the MAF sensor and ensure all connections are secure.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition on (do not start) to check for the fuel pressure reading. It should match the manufacturer's specifications (typically around 40-50 PSI).
  • If the pressure is low, check the fuel pump and filter for issues and replace if necessary.

5. Inspect and Test Fuel Injectors

• Sub-steps:
  • Remove the fuel injectors from the intake manifold (ensure to relieve fuel pressure first).
  • Clean the injectors using a specialized injector cleaning kit or replace them if they are clogged.
  • Reinstall the injectors ensuring proper seating and sealing.

6. Reassemble and Clear Codes

• Sub-steps:
  • Reassemble any components removed during the inspection.
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the check engine light codes.