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

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before working.

2. Inspect and Repair Air Intake System

• Inspect air intake: Check all hoses and connections for leaks or cracks.
• Repair or replace: If any damaged components are found, replace them with OEM or equivalent parts.
• Reattach: Ensure all connections are secure.

3. Clean or Replace MAF Sensor

• Remove MAF sensor: Disconnect the electrical connector and unscrew the sensor from the air intake.
• Clean sensor: Use MAF cleaner to gently clean the sensor elements. Avoid touching them with fingers or tools.
• Reinstall: Once dry, reinstall the MAF sensor and reconnect the electrical connector.

4. Inspect Fuel System

• Check fuel pressure: Use a fuel pressure gauge to verify that the fuel pressure is within specifications (typically around 40-50 psi for most systems).
• Replace fuel filter: If the fuel filter is clogged, replace it.
• Check fuel injectors: Inspect for leaks and test for proper operation. Replace any faulty injectors.

5. Test and Replace Oxygen Sensors (if necessary)

• Check sensor function: Using a multimeter or scan tool, test the voltage and response time of the upstream oxygen sensor.
• Replace sensor: If readings are out of specification, replace the oxygen sensor with an OEM part.