how to fix P0171 code in my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, fuel pressure gauge, socket set, vacuum gauge.
• Disconnect the battery to ensure safety while working on the electrical components.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Remove the air intake duct and inspect for cracks or loose fittings.
  • Replace any damaged components to ensure a tight seal.
  • Clean the MAF sensor with MAF cleaner to remove any debris. Allow it to dry completely.

3. Check and Repair Fuel System

• Sub-steps:
  • Attach the fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position without starting the engine.
  • Check the fuel pressure against the manufacturer's specifications (typically around 50-60 psi).
  • If pressure is low, inspect the fuel pump and fuel filter for blockages or failures.
  • Replace the fuel filter if necessary and test the fuel pump operation.

4. Inspect Vacuum Lines

• Sub-steps:
  • Visually inspect all vacuum lines connected to the intake manifold for cracks or disconnections.
  • Use a vacuum gauge to check for proper vacuum levels.
  • Replace any damaged vacuum lines or reattach loose connections.

5. Test Oxygen Sensors

• Sub-steps:
  • Locate the upstream oxygen sensor and remove it using a socket wrench.
  • Use a multimeter to check the sensor's resistance (consult specifications for correct values).
  • If the sensor is faulty, replace it with a new one.