how to address the check engine light and P0171 code in my Toyota Highlander XU70 (2020-Present)?

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers, flashlight
• Remove the air filter housing and inspect for cracks or loose connections.
• Check the integrity of all intake hoses and connections; replace damaged hoses.
• Reinstall the air filter housing securely.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, torx screwdriver
• Locate the MAF sensor in the air intake path.
• Disconnect the electrical connector and remove the sensor using a torx screwdriver.
• Clean the sensor with MAF sensor cleaner; do not touch the sensing element.
• Reinstall the sensor and reconnect the electrical connector.

4. Test and Repair the Fuel System

• Tools Required: Fuel pressure gauge, wrench set
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start) and check the fuel pressure; it should be within manufacturer specifications.
• If pressure is low, check the fuel pump and fuel filter for clogs or failures and replace as necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner, injector removal tool
• Remove the fuel injectors from the rail.
• Clean the injectors using a fuel injector cleaner or have them professionally cleaned.
• Reinstall the injectors and ensure they are sealed properly.