my Toyota RAV4 XA40 (2013-2018) keeps throwing a P0171 code, how to fix it?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, vacuum gauge.
• Disconnect the battery to ensure safety before starting work.

2. Inspect the Air Intake System

• Sub-steps:
  1. Remove the air intake duct by loosening the clamps using a socket set.
  2. Inspect the duct for cracks or signs of wear.
  3. Check the connections for tightness and integrity.
  4. Replace any damaged components as necessary.

3. Clean or Replace the MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake assembly.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the sensor using the socket set.
  4. Clean the sensor with MAF cleaner spray if it's dirty; otherwise, replace it with a new one.
  5. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel Delivery

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Attach a fuel pressure gauge to the port.
  3. Turn the ignition to the "ON" position (do not start the engine) and read the fuel pressure.
  4. Compare the pressure reading with the specifications (typically 30-50 psi for RAV4).
  5. If pressure is low, check the fuel pump and fuel filter for issues; replace as necessary.

5. Inspect Vacuum Lines

• Sub-steps:
  1. Conduct a visual inspection of all vacuum hoses connected to the intake manifold.
  2. Look for any signs of damage, such as cracks or holes.
  3. Replace any compromised vacuum hoses to ensure proper sealing.