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

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the intake ducting and hoses for cracks or disconnections.
  2. Tighten any loose clamps and replace damaged hoses.
  3. If an intake leak is found, replace the affected component.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake system.
  2. Disconnect the electrical connector and remove the sensor.
  3. Clean the MAF sensor with MAF cleaner or replace it if damaged.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail and turn the ignition on (do not start the engine).
  2. Check that the fuel pressure is within the manufacturer's specifications (typically around 50-60 psi).
  3. If the pressure is low, inspect the fuel pump and fuel filter.
  4. Replace the fuel filter if clogged, or the fuel pump if faulty.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the engine cover to access the fuel injectors.
  2. Check for fuel leaks around the injectors.
  3. If injectors are clogged, use a fuel injector cleaning kit or replace them.