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

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Socket set, screwdrivers
• Inspect all vacuum hoses and connections for cracks or disconnections.
• Replace any damaged hoses or reattach loose connections.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, Torx or socket wrench
• Remove the MAF sensor from the air intake duct.
• Clean the sensor with MAF cleaner according to the manufacturer's instructions.
• If damaged, replace the MAF sensor with a new one and reattach.

4. Check and Repair Fuel Delivery Issues

• Tools Required: Fuel pressure gauge, rags for spills
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start the engine) and check the fuel pressure.
• If pressure is low, inspect and possibly replace the fuel pump or fuel filter.

5. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench
• Locate the upstream oxygen sensor (usually before the catalytic converter).
• Remove the sensor using the O2 sensor socket and inspect for damage.
• Replace if necessary, applying anti-seize compound on the threads before installation.
• Torque to the manufacturer's specifications.

6. Reset the ECM

• Reconnect the battery and use the OBD-II scanner to clear the P0171 code from the ECM.