how to fix P0171 code on my Honda Civic 9th Generation (2012-2015)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down completely before starting work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, socket set, flashlight
• Instructions:
  1. Use a vacuum gauge to check for leaks in the intake system.
  2. Visually inspect all hoses and connections for cracks, wear, or disconnections.
  3. Repair or replace any damaged hoses or gaskets identified during inspection.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, Torx screwdriver
• Instructions:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the sensor using a Torx screwdriver.
  4. Clean the sensor carefully with MAF sensor cleaner, following the product instructions.
  5. Allow it to dry and reinstall it, reconnecting the electrical connector.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Instructions:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge to the test port.
  3. Turn the ignition key to the "On" position without starting the engine to check the pressure.
  4. Compare the reading with manufacturer specifications (should be typically around 40-50 PSI).
  5. If pressure is low, check the fuel pump operation and replace if necessary.

5. Replace Fuel Filter (if necessary)

• Tools Required: Socket set, fuel line disconnect tool
• Instructions:
  1. Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
  2. Disconnect the fuel lines using a fuel line disconnect tool.
  3. Remove the fuel filter from its mounting bracket.
  4. Install the new fuel filter, ensuring the flow direction is correct.
  5. Reconnect the fuel lines and replace the fuel pump fuse.