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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal from the battery to ensure safety.
• Allow the engine to cool before working on it.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, screwdriver set, hose clamps.
• Instructions:
  1. Use a vacuum gauge to check for leaks in the intake manifold.
  2. Visually inspect all vacuum hoses and gaskets. Look for cracks or disconnections.
  3. Replace any damaged hoses or gaskets.

3. Clean MAF Sensor

• Tools Required: MAF sensor cleaner, soft cloth.
• Instructions:
  1. Locate the MAF sensor (usually near the air filter).
  2. Disconnect the electrical connector and remove the sensor.
  3. Spray the MAF sensor with a specialized cleaner and allow it to dry completely before reinstallation.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Instructions:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine and check the fuel pressure reading.
  3. Compare the reading to manufacturer specifications. If the pressure is low, check the fuel pump and filter.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaner, small brush.
• Instructions:
  1. Remove the fuel injectors from the engine.
  2. Clean the injectors using an injector cleaning solution and a brush.
  3. Reinstall the injectors and ensure they are securely connected.

6. Clean Throttle Body

• Tools Required: Throttle body cleaner, soft cloth.
• Instructions:
  1. Disconnect the air intake duct from the throttle body.
  2. Use throttle body cleaner to clean the inside of the throttle body thoroughly.
  3. Reconnect the duct securely after cleaning.