how to fix P0171 code in Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdriver set
• Remove the air intake duct and inspect for any cracks or loose fittings.
• If any damage is found, replace the affected components.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or isopropyl alcohol, soft cloth
• Disconnect the MAF sensor electrical connector.
• Remove the MAF sensor from the air intake.
• Clean the sensor's wire or plate gently with MAF cleaner. If damaged, replace the sensor with a new one.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Locate the fuel rail pressure test port and connect the fuel pressure gauge.
• Turn the ignition to the "ON" position without starting the engine and check the fuel pressure.
• If the pressure is outside specifications, replace the fuel pump or filter as necessary.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaning kit
• Remove the fuel rail and inspect the injectors for clogs or leaks.
• If dirty, use a fuel injector cleaning kit to clean them. Replace any malfunctioning injectors.

6. Address Vacuum Leaks

• Tools Required: Vacuum gauge or smoke machine
• Use a vacuum gauge to test for leaks or use a smoke machine to identify leaks in the intake system.
• Replace any faulty gaskets, hoses, or components found during the inspection.