how to troubleshoot P0171 code on my Ford F-150 14th Generation (2021-2024)

Learn how to troubleshoot and fix P0171 lean air-fuel mixture in Ford F-150 14th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the battery to prevent electrical issues.

2. Inspect Air Intake System

• Remove the air filter and inspect for dirt or blockages.
• Check the intake manifold for any visible cracks or leaks.
• Tighten or replace any loose or damaged clamps and hoses.

3. Clean or Replace MAF Sensor

• Locate the MAF sensor in the air intake duct.
• Disconnect the electrical connector.
• Remove the MAF sensor using a socket set.
• Clean the MAF sensor with MAF cleaner or replace it if necessary.

4. Test Fuel System Pressure

• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition on without starting the engine to check the pressure reading.
• Compare the reading to manufacturer specifications (typically around 30-65 psi for most F-150 models).
• If pressure is low, check for fuel pump operation or clogged fuel filter.

5. Inspect Vacuum Hoses

• Visually inspect all vacuum hoses connected to the intake manifold.
• Replace any cracked or broken hoses.
• Use a smoke machine if available to detect vacuum leaks.

6. Check Engine Coolant Temperature Sensor

• Locate the coolant temperature sensor on the engine.
• Disconnect the electrical connector and use a multimeter to check resistance.
• If resistance is out of specified range, replace the sensor.