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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to avoid any electrical shorts.
• Allow the vehicle to cool down if it has been running.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Inspect the air intake hoses for cracks or disconnections.
  • Replace any damaged hoses with OEM parts.
  • Tighten any loose clamps or connections to ensure a proper seal.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake duct.
  • Use MAF sensor cleaner to clean the sensor elements.
  • Allow the sensor to dry completely before reinstalling.
  • If the sensor is damaged, replace it with a new one.

4. Check Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition on (do not start the engine) and check the fuel pressure reading.
  • Compare the reading with the manufacturer specifications (typically around 50-60 PSI).
  • If the pressure is low, check the fuel pump and fuel filter for issues and replace as necessary.

5. Inspect Vacuum Lines

• Sub-steps:
  • Visually inspect all vacuum lines for cracks or disconnections.
  • Replace any damaged lines with new vacuum hoses.
  • Ensure all connections are secure and tight.