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

Learn how to diagnose and fix P0171 engine too lean condition in Ford F-150 (2021-2024). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable to prevent electrical shorts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Inspect and Repair Intake System

• Sub-step 1: Visually inspect the air intake hose and gaskets for cracks or signs of wear.
• Sub-step 2: If any leaks are found, replace the damaged hoses or gaskets.
• Sub-step 3: Reconnect all intake components securely.

3. Fuel Pressure Check

• Sub-step 1: Attach a fuel pressure gauge to the fuel rail Schrader valve.
• Sub-step 2: Turn the ignition to the "ON" position (without starting the engine) to check the fuel pressure.
• Sub-step 3: Compare the reading with manufacturer specifications (typically around 55-65 psi). If pressure is low, replace the fuel pump or check for a clogged fuel filter.

4. Clean MAF Sensor

• Sub-step 1: Locate the MAF sensor in the air intake duct.
• Sub-step 2: Remove the sensor carefully, ensuring not to damage the wires.
• Sub-step 3: Use MAF cleaner spray to clean the sensor elements; do not touch the sensor with any tools.
• Sub-step 4: Reinstall the MAF sensor securely.

5. Inspect and Replace Oxygen Sensors

• Sub-step 1: Locate the upstream oxygen sensor on bank 1.
• Sub-step 2: Use an oxygen sensor socket to remove the old sensor.
• Sub-step 3: Install the new oxygen sensor and ensure it is torqued to the manufacturer's specifications (typically around 30 ft-lbs).
• Sub-step 4: Repeat for downstream sensor if necessary.

6. Final Checks

• Sub-step 1: Reconnect the negative battery cable.
• Sub-step 2: Start the engine and allow it to warm up. Check for any leaks or abnormal sounds.
• Sub-step 3: Clear the P0171 code using the OBD-II scanner and perform a test drive to verify the repair.