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

Learn how to diagnose and fix P0171 engine 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.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery cable for safety.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, various socket sizes
• Steps:
  1. Use a vacuum gauge to check for leaks in the intake manifold and associated vacuum hoses.
  2. Replace any damaged or cracked hoses and ensure all connections are tight.
  3. Inspect the intake manifold gasket for leaks and replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner or isopropyl alcohol, soft cloth
• Steps:
  1. Disconnect the wiring harness from the MAF sensor.
  2. Remove the MAF sensor from the air intake duct.
  3. Spray MAF sensor cleaner on the sensing element; do not touch it with tools or fingers.
  4. Allow it to dry completely, then reinstall the MAF sensor and reconnect the harness.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
  3. Observe the pressure reading; compare it with the specifications in the repair manual.
  4. If pressure is low, inspect the fuel pump, filter, and regulator for issues.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaner kit (if needed), multimeter
• Steps:
  1. Disconnect the fuel injector harness.
  2. Use a multimeter to check the resistance of each injector; compare readings to specifications.
  3. If any injectors are faulty, replace them. Clean injectors using an injector cleaning kit if necessary.

6. Inspect Throttle Body

• Tools Required: Throttle body cleaner, soft cloth
• Steps:
  1. Remove the air intake duct to access the throttle body.
  2. Clean the throttle body using throttle body cleaner and a cloth; ensure the butterfly valve operates freely.
  3. Reinstall the duct and ensure all hoses are connected properly.