how to diagnose P0171 code on my Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0171 engine too lean condition in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical issues while working on the engine.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use a smoke machine to check for vacuum leaks if needed.
  • Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake duct.
  • Clean the MAF sensor with MAF cleaner spray; do not touch the sensing element.
  • If damaged, replace the MAF sensor with a new one.

4. Check Fuel System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition key to the "ON" position (do not start the engine) and check the pressure. It should match the manufacturer's specifications (usually around 50-60 psi).
  • If the pressure is low, inspect the fuel pump and filter. Replace as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the fuel injectors from the fuel rail.
  • Clean the injectors using an ultrasonic cleaner or replace if clogged or malfunctioning.
  • Reinstall injectors ensuring proper sealing and connections.

6. Reset the Check Engine Light

• Sub-steps:
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the P0171 code.
  • Start the engine and check for any new codes.