how to fix P0171 lean condition code in my Honda Civic 9th Generation (2012-2015)?

Solution

1. Preparation

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

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Remove the engine cover if present.
  • Inspect all air intake hoses for cracks or disconnections; replace any damaged hoses.
  • Check the intake manifold gasket for leaks; replace if necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the Mass Air Flow sensor in the air intake duct.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the MAF sensor with MAF cleaner spray; allow it to dry completely before reinstalling.
  • If damaged, replace the MAF sensor with a new one.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (do not start) to check the fuel pressure reading.
  • If the pressure is below specifications (usually around 40-50 psi), inspect the fuel pump and filter; replace them if faulty.

5. Inspect and Clean Fuel Injectors

• Sub-steps:
  • Remove the fuel rail with the injectors attached.
  • Use an injector cleaning kit to clean each injector; follow the kit’s instructions.
  • Check for leaks when reinstalling the fuel rail.

6. Inspect Vacuum Lines

• Sub-steps:
  • Visually inspect all vacuum lines for cracks, breaks, or disconnections.
  • Replace any damaged vacuum hoses.
  • Check for proper routing of all hoses to prevent air leaks.