how to fix the P0174 code on my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  • Use a smoke machine to identify any hidden vacuum leaks.
  • Replace any damaged hoses with OEM parts.

3. Clean the Mass Airflow Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake duct.
  • Use MAF cleaner spray to clean the sensing element, avoiding physical contact.
  • Allow the sensor to dry completely before reinstalling.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail test port.
  • Start the engine and observe the fuel pressure. It should be within the range specified by the manufacturer (usually around 50-60 PSI).
  • If the pressure is low, inspect the fuel pump and filter. Replace as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the fuel rail to access the fuel injectors.
  • Inspect each injector for clogs or leaks, and clean or replace them as necessary.
  • Reinstall the fuel rail, ensuring proper torque specifications are followed.

6. Reconnect Battery and Erase Codes

• Reconnect the negative battery cable.
• Use the OBD-II scanner to clear the P0174 code and reset the check engine light.