how to fix P0171 code in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

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

2. Inspect and Repair Air Intake System

• Tools Required: Vacuum gauge, hose clamps, screwdriver
• Check all hoses and connections in the air intake system for wear or damage.
• Replace any damaged hoses and ensure all connections are tight.
• Use a vacuum gauge to check for leaks; repair as needed.

3. Clean MAF Sensor

• Tools Required: MAF sensor cleaner or electrical cleaner
• Remove the MAF sensor from the air intake duct.
• Spray the MAF sensor with MAF cleaner to remove dirt and debris.
• Allow it to dry completely before reinstalling it.

4. Test and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position (without starting the engine) to check the pressure.
• If the pressure is below specifications, inspect the fuel pump and fuel filter. Replace if necessary.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaning kit (optional), multimeter
• If fuel pressure is adequate, check the injectors for proper function. Use a multimeter to check resistance.
• Clean or replace any faulty injectors.