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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical issues during repairs.
• Ensure the engine is cool before beginning work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, flashlight
• Check the air filter for dirt and replace if necessary.
• Visually inspect air intake hoses for cracks or loose connections and replace any faulty components.

3. Clean or Replace MAF Sensor

• Tools Required: Screwdriver, MAF cleaner
• Carefully remove the MAF sensor from the air intake duct.
• Spray MAF cleaner onto the sensor wires and components. Allow it to dry completely before reinstallation.

4. Fuel System Inspection

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading against specifications (usually around 30-50 psi). If pressure is low, inspect the fuel pump and filter.

5. Check Fuel Injectors

• Tools Required: Multimeter, injector cleaner
• Use a multimeter to test the resistance of each fuel injector. Replace any injectors that are outside the manufacturer’s specified range.
• If injectors are clogged, use an injector cleaning kit to clean them.

6. Oxygen Sensor Inspection

• Tools Required: O2 sensor socket, multimeter
• Locate the upstream (pre-catalytic converter) oxygen sensor and check its wiring for damage.
• Use a multimeter to verify the sensor’s voltage output while the engine is running. If it is not within the specified range, replace the sensor.