how do I fix P0171 code in my Ford F-150 Fourteenth Generation (2021-present)

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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical issues during repairs.
• Allow the engine to cool completely before working on it.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, socket set, screwdrivers
• Visually inspect all vacuum hoses for cracks or damage.
• Use a vacuum gauge to measure the vacuum; a reading below normal indicates a leak.
• Replace any damaged hoses or gaskets.

3. Clean or Replace the MAF Sensor

• Tools Required: MAF cleaner, Torx screwdriver
• Locate the MAF sensor in the intake system.
• Disconnect the electrical connector and remove the sensor using the Torx screwdriver.
• Clean the sensor with MAF cleaner; allow it to dry completely before reinstalling.
• If the sensor is damaged, replace it with a new one.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail test port.
• Turn the ignition to the "On" position without starting the engine to check fuel pressure.
• Ensure the pressure is within manufacturer's specifications; replace the fuel pump if it's low.

5. Inspect Exhaust System

• Tools Required: Visual inspection tools, wrench set
• Inspect the exhaust manifold, pipes, and catalytic converter for leaks or blockages.
• Repair any leaks with appropriate exhaust sealant or replace damaged components.

6. Test Engine Coolant Temperature Sensor

• Tools Required: Multimeter
• Disconnect the sensor connector and test resistance using a multimeter.
• Compare readings to specifications in the service manual; replace the sensor if out of range.