how to fix P0171 code in Toyota Corolla E210 (2019-2024) for a lean condition?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Use a smoke machine or soapy water to check for vacuum leaks around hoses, gaskets, and connections.
• If any leaks are found, replace the damaged hoses or gaskets as needed.

3. Clean or Replace MAF Sensor

• Disconnect the wiring harness from the MAF sensor.
• Remove the MAF sensor from the air intake tube using a socket set.
• Clean the MAF sensor with MAF cleaner spray and allow it to dry.
• If damaged, replace the MAF sensor with a new one.

4. Test Fuel Pressure

• Connect a fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position without starting the engine and check the pressure reading against manufacturer specifications (typically 43-50 psi for most Toyotas).
• If pressure is low, check the fuel pump and fuel filter, replacing as necessary.

5. Check and Replace Fuel Injectors

• Remove the fuel injector connector and inspect for any signs of damage.
• Use a multimeter to test the resistance of the injectors; replace if out of specification.
• If clogged, remove the injectors and clean them using an ultrasonic cleaner or replace them.

6. Reassemble and Clear Codes

• Reinstall all components and reconnect the battery.
• Start the engine and let it reach operating temperature.
• Use the OBD-II scanner to clear the P0171 code and perform a test drive to ensure the code does not reappear.