how to fix P0171 lean condition in Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use a smoke machine or carburetor cleaner to identify any leaks.
  • Replace any damaged hoses or gaskets found during inspection.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Disconnect the electrical connector and remove the sensor from the duct.
  • Clean the MAF sensor using MAF cleaner spray; do not touch the sensor with fingers.
  • If cleaning does not resolve issues, replace the MAF sensor with a new one.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the Schrader valve on the fuel rail.
  • Turn the ignition to the "ON" position (do not start) to check for pressure.
  • Compare the reading with manufacturer specifications (typically around 43-50 psi).
  • If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockages or damage.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  • Remove the fuel rail to access the injectors.
  • Inspect the injectors for dirt or clogging.
  • Use a professional fuel injector cleaner or replace injectors if necessary.
  • Reassemble the fuel rail with new seals to prevent leaks.