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

Learn how to diagnose and fix P0171 fuel system issue in Ford F-150 (2009-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable to prevent electrical shorts.
• Ensure the vehicle is on a level surface and the engine is cool.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Hose clamps, vacuum gauge
• Use a vacuum gauge to check for vacuum leaks in the intake system.
• Inspect all hoses, gaskets, and connections for signs of wear or damage.
• Repair or replace any damaged components.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Carefully remove the MAF sensor from the air intake.
• Spray the MAF sensor with a specialized cleaner, ensuring not to touch the sensor wires.
• Allow it to dry completely before reinstalling.
• If the sensor is damaged, replace it with a new one.

4. Test and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine and check the pressure.
• Compare the reading to the manufacturer's specification; if low, check the fuel pump and filter for issues, and replace if necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner kit (optional), ratchet set
• Remove the fuel rail from the engine carefully to access the injectors.
• Inspect each injector for clogs or leaks.
• Clean the injectors using an appropriate cleaning kit or replace them if necessary.

6. Check Oxygen Sensor

• Tools Required: Multimeter, socket set
• Inspect the wiring and connector of the oxygen sensor for damage.
• Use a multimeter to test the sensor's voltage output; refer to the specific voltage range for your vehicle.
• Replace the oxygen sensor if it is not functioning correctly.