how to fix P0171 lean code on Ford F-150 13th Generation (2015-2020)

Learn how to diagnose and fix P0171 lean code in Ford F-150 13th Generation (2015-2020). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

Solution

1. Preparation

• Gather tools and equipment: OBD-II scanner, multimeter, fuel pressure gauge, vacuum gauge, socket set, and safety glasses.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Repair Air Intake System

• Sub-step 1: Visually inspect all vacuum hoses for cracks or disconnections. Replace any damaged hoses.
• Sub-step 2: Check the intake manifold gasket for leaks. If damaged, remove the intake manifold and replace the gasket.
• Sub-step 3: Inspect the throttle body for carbon buildup and clean it with throttle body cleaner.

3. Clean or Replace MAF Sensor

• Sub-step 1: Remove the MAF sensor from the air intake duct.
• Sub-step 2: Clean the sensor with MAF cleaner and allow it to dry completely before reinstalling.
• Sub-step 3: If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Test and Repair Fuel System

• Sub-step 1: Connect the fuel pressure gauge to the fuel rail and turn the ignition to the ON position (do not start the engine) to check fuel pressure levels against manufacturer specifications.
• Sub-step 2: If the pressure is low, inspect the fuel filter for clogs and replace it if necessary.
• Sub-step 3: Check the fuel pump operation and replace if it does not meet pressure specifications.

5. Inspect and Clean Fuel Injectors

• Sub-step 1: Use a fuel injector cleaner additive in the fuel tank or remove injectors for ultrasonic cleaning.
• Sub-step 2: If injectors are clogged or damaged, replace them as necessary.

6. Verify Oxygen Sensor Functionality

• Sub-step 1: Use a multimeter to check the voltage output of the oxygen sensors. Replace any malfunctioning sensors.