how to fix P0171 code in Ford F-150 12th Generation (2009-2014)

Learn how to diagnose and fix P0171 lean fuel condition in Ford F-150 12th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.
• Allow the engine to cool before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Remove the air intake duct by loosening the clamps and disconnecting any sensors.
  • Visually inspect the duct for cracks or leaks. Replace if damaged.
  • Check the throttle body for carbon buildup and clean it using throttle body cleaner.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Disconnect the MAF sensor harness and remove the sensor from the air intake tube.
  • Use MAF cleaner to spray and clean the sensor components; do not touch the sensor element.
  • Reinstall the MAF sensor, ensuring a secure fit and reconnect the harness.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail service port.
  • Turn the ignition to the "ON" position (do not start the engine) and check the pressure against specifications in the repair manual.
  • If pressure is low, check the fuel pump and filter for blockages or failure. Replace as necessary.

5. Inspect and Repair Vacuum Lines

• Sub-steps:
  • Visually inspect all vacuum lines for cracks or disconnections, especially around the intake manifold.
  • Replace any damaged lines and ensure all connections are tight.

6. Test Fuel Injectors

• Sub-steps:
  • Use a multimeter to test the resistance of each injector; compare readings to manufacturer specifications.
  • Clean injectors using a fuel injector cleaning kit if they are clogged or replace them if faulty.