how to fix P0171 code in Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather required tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:

  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to detect leaks while the engine is running.
  3. Replace any damaged hoses or gaskets found during inspection.

• Tools Required: Smoke machine or carburetor cleaner, hose clamps, replacement hoses.

3. Clean MAF Sensor

• Sub-steps:

  1. Remove the MAF sensor from the air intake duct.
  2. Use MAF sensor cleaner to spray the sensing elements.
  3. Allow the sensor to dry completely before reinstalling.

• Tools Required: Torx or screwdriver set, MAF sensor cleaner.

4. Test and Repair Fuel System

• Sub-steps:

  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine to check pressure.
  3. Compare the readings to manufacturer specifications; replace the fuel pump or filter if pressure is low.

• Tools Required: Fuel pressure gauge, replacement fuel pump/filter if needed.

5. Clean or Replace Throttle Body

• Sub-steps:

  1. Remove the throttle body from the intake manifold by loosening the bolts.
  2. Clean the throttle plate and bore using throttle body cleaner.
  3. Reinstall the throttle body with new gaskets and torque bolts to manufacturer specifications.

• Tools Required: Throttle body cleaner, socket set, torque wrench.