how to fix the P0174 code in my Toyota RAV4 Fourth Generation (2013-2018)?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, vacuum gauge, multimeter.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold and throttle body for cracks or disconnections.
  2. Use a vacuum gauge to test for leaks; ideally, you should see a steady reading within the normal range.
  3. If leaks are found, replace damaged hoses or use vacuum sealant on any cracks.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor using a socket.
  3. Clean the MAF sensor with MAF sensor cleaner; avoid touching the sensor element.
  4. If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the "On" position (without starting the engine) and check the fuel pressure; it should be within the manufacturer's specifications.
  3. If the pressure is low, inspect the fuel pump and replace the fuel filter if clogged.
  4. Ensure the fuel injectors are clean and functioning properly.

5. Inspect Exhaust System

• Sub-steps:
  1. Visually inspect the exhaust system for any signs of leaks, particularly before the oxygen sensor.
  2. Use a smoke machine or soapy water to detect leaks in the exhaust.
  3. Repair or replace any damaged exhaust components as needed.

6. Replace Oxygen Sensor (if necessary)

• Sub-steps:
  1. Locate the oxygen sensor on Bank 2.
  2. Disconnect the sensor’s electrical connector and unscrew it from the exhaust pipe using a socket.
  3. Install the new sensor, ensuring it is properly torqued to avoid leaks.
  4. Reconnect the electrical connector.