how to fix P0171 code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to avoid any electrical issues while working.
• Allow the engine to cool before proceeding.

2. Inspect and Repair Air Intake System

• Tools Required: Vacuum gauge, socket set
• Sub-steps:
  1. Visually inspect the air intake hoses for cracks or loose connections.
  2. Use a vacuum gauge to check for leaks in the intake system.
  3. Tighten any loose clamps or replace damaged hoses as needed.

3. Clean or Replace the MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver set
• Sub-steps:
  1. Locate the MAF sensor along the air intake duct.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Unscrew the MAF sensor from the intake.
  4. Spray the MAF sensor with MAF cleaner and allow it to dry completely.
  5. Reinstall the MAF sensor and reconnect the electrical connector.

4. Inspect and Test Fuel System

• Tools Required: Fuel pressure gauge, socket set
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail service port.
  2. Turn the ignition to the "ON" position without starting the engine and check for fuel pressure.
  3. Compare the reading to the manufacturer’s specifications; it typically should be between 50-60 PSI for the RAV4.
  4. If the pressure is low, check the fuel pump, filter, and lines for issues.

5. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Disconnect the electrical connectors from each sensor.
  3. Use the O2 sensor socket to remove the sensors from the exhaust.
  4. Install new oxygen sensors, ensuring they are torqued to manufacturer specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connectors.