how to fix P0174 code in my Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before working on the intake components.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Remove the air intake duct and inspect for any cracks or damage.
  2. Check all hose connections and clamps for tightness.
  3. Replace any damaged hoses or components as needed.

3. Clean the MAF Sensor

• Sub-steps:
  1. Remove the MAF sensor from the air intake.
  2. Use MAF cleaner spray to clean the sensor element; do not touch it directly.
  3. Reinstall the MAF sensor securely.

4. Check and Adjust Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine and check the fuel pressure; it should be within manufacturer specifications (typically 40-50 psi).
  3. If the pressure is low, inspect the fuel pump and fuel filter for issues; replace if necessary.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail and injectors.
  2. Clean the injectors using an ultrasonic cleaner or replace if clogged.
  3. Reassemble the fuel rail and ensure all connections are secure.