how to fix Honda Pilot YF3 (2016-2022) P0171 system too lean code

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect the intake manifold, vacuum hoses, and throttle body for cracks or disconnections.
  • Use a smoke machine to detect vacuum leaks if necessary.
  • Replace or tighten any damaged or loose components.
• Tools Required:
  • Smoke machine (optional)
  • Screwdriver set
  • Pliers

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor on the air intake duct.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the sensor with MAF cleaner or replace it if damaged.
  • Reinstall the sensor and reconnect the electrical connector.
• Tools Required:
  • MAF cleaner
  • Torx or Phillips screwdriver

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) and check the fuel pressure reading.
  • If the pressure is low, inspect the fuel pump, filter, and lines for blockages or failures and replace as necessary.
• Tools Required:
  • Fuel pressure gauge
  • Socket set

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the fuel rail to access the injectors.
  • Inspect the injectors for clogs or leaks.
  • Clean or replace any faulty injectors.
• Tools Required:
  • Socket set
  • Injector cleaning kit (if cleaning)

6. Verify ECT Sensor Functionality

• Sub-steps:
  • Locate the ECT sensor and disconnect the electrical connector.
  • Use a multimeter to test the sensor’s resistance against the manufacturer’s specifications.
  • Replace the sensor if it is out of specification.
• Tools Required:
  • Multimeter
  • Socket set