how to fix P0171 code in Ford F-150 14th Generation (2021-2024)

Learn how to diagnose and fix P0171 fuel system issue in Ford F-150 (2021-2024). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before beginning work.

2. Inspect for Vacuum Leaks

• Tools Required: Vacuum gauge, flashlight
• Use a vacuum gauge to check for leaks in the intake manifold and hoses.
• Visually inspect all vacuum lines and connections for cracks or disconnections.
• Repair or replace any damaged hoses or gaskets found during inspection.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, Torx screwdriver
• Locate the MAF sensor, which is typically between the air filter and throttle body.
• Remove the MAF sensor from its housing using the Torx screwdriver.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely.
• Reinstall the MAF sensor ensuring it is secured properly.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail's test port.
• Turn the ignition to the "on" position without starting the engine and check the pressure reading.
• If the pressure is below specifications (consult service manual for exact numbers), inspect the fuel pump and filters for issues.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaning kit, multimeter (optional)
• Use an injector cleaning kit to clean the fuel injectors if clogged.
• Alternatively, check the electrical connector to the injectors using a multimeter for proper voltage and resistance.
• Replace any faulty injectors as necessary.

6. Air Filter Inspection

• Tools Required: None
• Locate the air filter housing and remove the cover.
• Inspect the air filter for dirt and debris.
• Replace the air filter if it appears clogged or dirty.