my Ford F-150 Fourteenth Generation (2021-present) has a check engine light and code P0171 what does...

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

Solution

1. Preparation

• Gather necessary tools and materials.
• Disconnect the battery (negative terminal) to ensure safety.
• Allow the engine to cool completely before starting work.

2. Inspect Air Intake System

• Tools Required: Vacuum gauge, flashlight, and possibly a socket set.
• Visually inspect air intake hoses and connections for cracks, wear, or disconnections.
• Use a vacuum gauge to check for vacuum leaks; repair or replace any damaged components.

3. Test Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail according to the manufacturer's specifications.
• Turn the ignition to the ON position (do not start the engine) and check the pressure reading.
• If the pressure is below specification, inspect the fuel pump, fuel filter, and fuel lines for restrictions or failures.

4. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner or isopropyl alcohol, screwdriver.
• Locate the MAF sensor, disconnect the electrical connector, and remove it from the air intake duct.
• Spray the MAF sensor with cleaner and allow it to dry completely before reinstalling.
• If the MAF sensor is damaged, replace it with a new one.

5. Inspect and Test Oxygen Sensors

• Tools Required: O2 sensor socket, multimeter.
• Locate the upstream oxygen sensor and disconnect the electrical connector.
• Use a multimeter to test the sensor's voltage output; refer to specifications for proper values.
• Replace the oxygen sensor if it is not functioning within the specified range.

6. Clear Codes and Recheck

• Use the OBD-II scanner to clear the DTC codes.
• Start the engine and allow it to reach operating temperature while monitoring for the check engine light.