how to fix P0171 code in Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers
• Inspect the air intake duct for cracks or loose fittings.
• Tighten or replace any loose or damaged hoses.
• Check the air filter; replace if dirty or clogged.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, torque wrench
• Remove the MAF sensor from the air intake tube (usually held by screws).
• Spray MAF cleaner on the sensor element and let it dry completely before reinstalling.
• If the sensor is damaged, replace it with a new one and install it according to the manufacturer's torque specifications.

4. Test Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start the engine) and check the pressure.
• If the pressure is below specification, inspect the fuel pump and filter; replace if necessary.

5. Check and Clean Fuel Injectors

• Tools Required: Injector cleaning kit, torque wrench
• Remove the fuel injectors from the engine.
• Use an injector cleaning kit to clean the injectors; follow the kit instructions.
• Reinstall the injectors, ensuring they are seated properly and torqued to specifications.