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

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

Solution

1. Preparation

• Gather tools and materials.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Fuel pressure gauge
• Socket set
• Screwdriver set
• Multimeter
• Vacuum gauge

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses for cracks or signs of wear.
  2. Tighten or replace any loose or damaged hoses.
  3. Remove the air intake duct and inspect for obstructions.
  4. Clean the MAF sensor using MAF cleaner spray. Allow it to dry completely before reinstallation.

3. Check Fuel Delivery

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail service port.
  2. Turn the ignition key to the "On" position (do not start the engine) and check the fuel pressure reading. It should match the specifications listed in the service manual (typically around 55-65 psi for Ford F-150).
  3. If pressure is low, check the fuel filter, fuel pump, and fuel lines for blockages or failures. Replace any faulty components.

4. Inspect Vacuum Lines

• Sub-steps:
  1. Locate and trace all vacuum hoses connected to the intake manifold.
  2. Use a vacuum gauge to check for proper vacuum levels; replace any damaged hoses.
  3. Ensure all connections are secure and free from leaks.

5. Check Exhaust System

• Sub-steps:
  1. Inspect the exhaust manifold and pipes for any visible cracks or holes.
  2. Repair or replace any damaged components that could lead to exhaust leaks.