how to fix P0171 code in Ford F-150 Fourteenth Generation (2021-present)

Learn how to diagnose and fix P0171 fuel system issue in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting any work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all air intake hoses and connections for cracks or disconnections.
  2. Replace any damaged hoses or clamps.
  3. Use a smoke machine to identify hidden vacuum leaks if necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor's electrical connector.
  2. Remove the MAF sensor using a Torx screwdriver.
  3. Clean the sensor with MAF cleaner; do not touch the sensor element directly.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Test and Adjust Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start) and check the pressure reading against manufacturer specifications (typically around 50-60 psi).
  3. If the pressure is low, check the fuel pump and fuel filter; replace if necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Disconnect the fuel injector connectors.
  2. Remove the fuel rail and inspect the injectors for clogs or leaks.
  3. Clean or replace any faulty injectors.
  4. Reinstall the fuel rail and reconnect the injectors.

6. Check ECT Sensor

• Sub-steps:
  1. Locate the ECT sensor on the engine.
  2. Disconnect the sensor connector.
  3. Test the sensor using a multimeter for proper resistance readings according to specifications.
  4. Replace if readings are out of range.