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

Solution

1. Preparation

• Gather all 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

• 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 spray to identify any leaks.
  3. Replace any damaged hoses and ensure all connections are secure.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner or isopropyl alcohol, screwdriver set.
• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor using a screwdriver.
  3. Spray the MAF sensor with MAF cleaner and allow it to dry completely.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Sub-steps:
  1. Locate the fuel rail and connect the fuel pressure gauge to the test port.
  2. Turn the ignition to the "ON" position (without starting the engine) and observe the pressure reading.
  3. Compare the reading to manufacturer specifications (typically between 40-50 psi for the Honda Pilot).
  4. If pressure is low, check the fuel pump and fuel filter for issues.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaning kit or replacement injectors.
• Sub-steps:
  1. Remove the fuel rail and inspect the injectors for clogs or leaks.
  2. If clogged, clean the injectors using an injector cleaning kit.
  3. Reinstall the injectors and fuel rail ensuring all connections are tight.

6. Test and Replace ECT Sensor if Necessary

• Tools Required: Multimeter.
• Sub-steps:
  1. Locate the ECT sensor and disconnect the electrical connector.
  2. Use a multimeter to check the resistance values against manufacturer specifications.
  3. If the readings are outside the specified range, replace the ECT sensor.