how to fix P0171 code in Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Fuel pressure gauge
• Vacuum gauge

2. Inspect and Repair Air Intake System

• Inspect Hoses:

  • Visually inspect all hoses connected to the air intake for any cracks or leaks.
  • Tighten or replace any loose or damaged hoses.

• Check MAF Sensor:

  • Disconnect the MAF sensor connector.
  • Remove the MAF sensor using a socket set.
  • Clean the MAF sensor with MAF cleaner spray; allow it to dry completely before reinstallation.
  • Reinstall the sensor and reconnect the electrical connector.

3. Test and Repair Fuel System

• Check Fuel Pressure:

  • Connect the fuel pressure gauge to the fuel rail's test port.
  • Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading. It should match the manufacturer specifications (typically around 40-50 psi for most Honda engines).

• Inspect Fuel Filter and Pump:

  • If the pressure is low, check the fuel filter and replace if clogged.
  • Test the fuel pump operation; if defective, replace the fuel pump.

4. Inspect for Vacuum Leaks

• Check for Leaks:
  • Use a vacuum gauge to check the intake manifold vacuum.
  • If the reading is low, inspect all vacuum hoses, gaskets, and the intake manifold itself for leaks.
  • Replace any damaged gaskets or hoses found during inspection.