how to fix P0171 code in Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, smoke machine (optional)
• Sub-steps:
  • Use a vacuum gauge to check for proper vacuum levels.
  • Visually inspect all vacuum hoses and connections for cracks or damage.
  • If available, use a smoke machine to detect hidden leaks.
  • Repair or replace any damaged hoses or gaskets.

3. Check Fuel System

• Tools Required: Fuel pressure gauge
• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (without starting the engine) to check fuel pump operation.
  • Compare the pressure reading to manufacturer specifications (typically around 40-50 psi for Honda).
  • If pressure is low, inspect the fuel pump and filter. Replace if necessary.

4. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner
• Sub-steps:
  • Locate the MAF sensor in the intake tract.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the sensor with MAF sensor cleaner, ensuring no residue remains.
  • Reinstall and reconnect the sensor.

5. Inspect and Clean Throttle Body

• Tools Required: Throttle body cleaner, soft cloth
• Sub-steps:
  • Remove the air intake duct to access the throttle body.
  • Inspect for carbon buildup or obstructions.
  • Spray throttle body cleaner onto a soft cloth and wipe the throttle body interior.
  • Ensure the throttle plate moves freely and reinstall the air intake duct.

6. Test Oxygen Sensor

• Tools Required: Multimeter
• Sub-steps:
  • Locate the upstream oxygen sensor (before the catalytic converter).
  • Use a multimeter to check the sensor voltage output while the engine is running.
  • If the readings are outside of the normal range (0.1-0.9 volts), replace the oxygen sensor.