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

Learn how to diagnose and fix P0171 engine too lean condition in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery negative terminal to avoid electrical shorts.
• Allow the engine to cool down before beginning work.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses and connections for cracks or disconnections.
  • Use carburetor cleaner or smoke test to identify leaks.
  • Replace any damaged hoses or seals.

3. Clean the Mass Air Flow (MAF) Sensor

• Tools Required: MAF sensor cleaner
• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Carefully remove the sensor from its housing.
  • Spray the MAF sensor cleaner on the sensing elements, avoiding contact with the sensor body.
  • Allow the sensor to dry completely before reinstalling.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Sub-steps:
  • Attach the fuel pressure gauge to the fuel rail service port.
  • Start the engine and check the fuel pressure reading against the specifications (typically around 50-60 psi for the F-150).
  • If the pressure is low, check the fuel pump and filter for issues and replace if necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Injector cleaning kit or replacement injectors
• Sub-steps:
  • Remove the fuel rail assembly to access the injectors.
  • Inspect the injectors for dirt or clogs.
  • Clean the injectors using an appropriate cleaning solution or replace them if they are faulty.

6. Replace Faulty Oxygen Sensors

• Sub-steps:
  • Locate the upstream oxygen sensor on Bank 1.
  • Disconnect the electrical connector and unscrew the sensor using an oxygen sensor socket.
  • Install the new oxygen sensor and reconnect the electrical connector.