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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical issues.

2. Inspect Air Intake System

• Tools Required: Vacuum gauge, flashlight
• Visually inspect all vacuum hoses for cracks or disconnections.
• Use a vacuum gauge to check for leaks; a low reading indicates a possible vacuum leak.
• Inspect the intake manifold gasket for signs of wear or damage.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, Torx screwdriver
• Remove the MAF sensor from the air intake duct by unscrewing it.
• Spray MAF cleaner onto the sensor element; do not touch it with fingers or tools.
• Allow it to dry completely before reinstalling it.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Attach the fuel pressure gauge to the fuel rail test port.
• Turn the ignition key to the ON position (do not start the engine) and check the pressure reading.
• Compare the reading to the specifications in the service manual; if it is below specifications, inspect the fuel pump and fuel filter.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaning kit, multimeter
• Disconnect the fuel injectors and check for electrical continuity using a multimeter.
• If any injectors are faulty, replace them.
• Optionally, use an injector cleaning kit to clean clogged injectors.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code from the ECM.
• Start the engine and monitor for any new codes.