how to fix P0171 code in Ford F-150 14th Generation (2021-2024)

Learn how to diagnose and fix P0171 lean condition in Ford F-150 14th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, MAF cleaner, socket set, torque wrench.
• Disconnect the battery negative terminal to prevent electrical shorts.
• Allow the engine to cool before working on components.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Check the air intake hose for cracks, tears, or loose fittings; replace if damaged.
  3. Inspect the throttle body for carbon buildup and clean it with throttle body cleaner if necessary.
  4. Tighten any loose clamps and ensure a secure connection.

3. Check Fuel System

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position without starting the engine, and check the fuel pressure against manufacturer specifications.
  3. If the pressure is low, inspect the fuel pump and filter; replace if necessary.
  4. If the pressure is adequate, ensure that the fuel injectors are clean and functioning by performing a flow test.

4. Inspect and Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor using a socket set.
  3. Clean the MAF sensor wires with MAF cleaner; do not touch the wires with your fingers.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

5. Check Vacuum Lines

• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold for cracks, tears, or disconnections.
  2. Replace any damaged hoses with new ones of the same diameter and length.
  3. Ensure all connections are tight and secure.