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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, fuel pressure gauge, socket set, screwdrivers
• Clear any existing trouble codes with the OBD-II scanner after completing diagnostics.

2. Inspect and Repair the Air Intake System

• Sub-steps:
  1. Turn off the engine and disconnect the negative battery terminal.
  2. Visually inspect the air intake hose for cracks or looseness; replace if damaged.
  3. Check the air filter and replace it if it is dirty or clogged.
  4. Reconnect any loose connections or secure any clamps that may be causing air leaks.

3. Clean or Replace the MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the wiring harness from the MAF sensor.
  3. Remove the MAF sensor using a socket wrench.
  4. Clean the sensor using MAF cleaner; do not touch the sensor elements.
  5. Reinstall the MAF sensor and reconnect the wiring harness.

4. Check Fuel Pressure

• Sub-steps:
  1. Locate the fuel rail on the engine.
  2. Connect the fuel pressure gauge to the test port on the fuel rail.
  3. Turn the ignition key to the "ON" position (but do not start the engine) to check the fuel pressure; compare with manufacturer specifications.
  4. If pressure is low, inspect the fuel pump and fuel filter for issues, and replace if necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the engine cover to access the fuel injectors.
  2. Inspect each injector for leaks or clogs.
  3. Clean clogged injectors with an appropriate cleaner or replace them if they are faulty.

6. Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or damage.
  2. Replace any damaged hoses.
  3. Use smoke testing if necessary to identify hard-to-find leaks.