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

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 shock.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, vacuum gauge, inspection mirror
• Check all intake hoses and connections for cracks or loose fittings.
• Repair or replace any damaged hoses.
• Use a vacuum gauge to check for any vacuum leaks in the intake system.

3. Clean or Replace MAF Sensor

• Tools Required: Torx screwdriver, MAF sensor cleaner
• Locate the MAF sensor on the air intake duct.
• Disconnect the electrical connector and remove the sensor using a Torx screwdriver.
• Clean the sensor with MAF cleaner and allow it to dry completely before reinstalling. If damaged, replace the sensor.

4. Test and Repair Fuel System

• Tools Required: Fuel pressure gauge, wrench set
• Connect a fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position without starting the engine to check pressure.
• Compare the reading to the specifications in the service manual.
• If pressure is low, inspect the fuel pump, filter, and regulator for issues and replace if necessary.

5. Verify Oxygen Sensor Function

• Tools Required: Multimeter
• With the engine running, use a multimeter to check the voltage output from the upstream O2 sensor.
• The voltage should fluctuate between 0.1V and 0.9V. If it remains constant, the sensor may need replacement.

6. Reassemble and Test

• Reconnect all components and ensure there are no loose connections.
• Reconnect the negative battery terminal.
• Clear the P0171 code using the OBD-II scanner and perform a test drive to check for code reoccurrence.