my Toyota Highlander XU70 (2020-Present) has a P0171 code, what does that indicate?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Fix Vacuum Leaks

• Tools Required: Vacuum gauge, socket set
• Visually inspect all vacuum lines and hoses for cracks or disconnections.
• Use a vacuum gauge to test the intake system for leaks. If leaks are found, replace the damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Remove the MAF sensor from its housing carefully.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely before reinstalling it.
• If the MAF sensor is damaged, replace it with a new one.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition key to the "ON" position (do not start the engine) to check the fuel pressure. Compare it to the manufacturer's specifications.
• If the pressure is below specifications, check the fuel filter and pump, replacing them if necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner, socket set
• Remove the fuel injectors from the rail.
• Use a fuel injector cleaning kit to clean the injectors. If they are damaged, replace them with new ones.