how to fix P0171 code on Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool.

2. Inspect and Repair Air Intake System

• Tools Required: Screwdriver set, vacuum gauge.
• Inspect all hoses connected to the air intake system for cracks or loose connections.
• Replace any damaged hoses.
• Safety Warning: Ensure the engine is cool to avoid burns.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner (or isopropyl alcohol), soft cloth.
• Remove the MAF sensor from the air intake duct.
• Spray the MAF sensor with the cleaner and let it dry completely.
• Reinstall the sensor securely.
• If cleaning does not help, replace the MAF sensor with a new one.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition key to the "ON" position without starting the engine.
• Check the pressure reading against manufacturer specifications (should typically be between 35-50 psi).
• If pressure is low, inspect the fuel pump and filter for issues; replace as necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner kit.
• If fuel pressure is acceptable, remove the fuel injectors.
• Clean the injectors using a fuel injector cleaning kit or replace if they are clogged or leaking.
• Reinstall the injectors and ensure all connections are secure.

6. Reassemble and Test

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Ensure all components are securely reattached.