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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to prevent any electrical short circuits.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Remove the air intake duct and visually inspect for cracks or loose connections.
  • Replace any damaged hoses or gaskets.
  • Reattach the air intake duct securely.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Disconnect the electrical connector from the MAF sensor.
  • Remove the MAF sensor from the air intake housing.
  • Clean the MAF sensor using MAF sensor cleaner and let it dry completely.
  • Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Repair Fuel System

• Sub-steps:
  • Use a fuel pressure gauge to check the fuel pressure against manufacturer specifications.
  • If the pressure is low, inspect the fuel pump and replace the fuel filter if necessary.
  • If the fuel pump needs replacement, remove the rear seat or access panel to access the pump and follow manufacturer guidelines for installation.

5. Inspect Vacuum Lines

• Sub-steps:
  • Visually inspect all vacuum lines for cracks or disconnections.
  • Replace any damaged vacuum lines and ensure all connections are tight.

6. Inspect O2 Sensors

• Sub-steps:
  • Locate the upstream and downstream O2 sensors.
  • Use a multimeter to check the sensor’s voltage and response times.
  • Replace any faulty O2 sensors as needed.