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

Learn how to diagnose and fix P0171 engine lean condition in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts while working on the vehicle.
• Allow the engine to cool before proceeding with any repairs.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses for cracks or disconnections.
  2. Remove and replace any damaged hoses.
  3. Check the intake manifold for vacuum leaks using a smoke machine or carburetor cleaner.
  4. If leaks are found, replace the intake manifold gasket as necessary.

3. Fuel System Inspection

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start) and check the fuel pressure reading against manufacturer specifications (typically around 30-50 psi).
  3. If pressure is low, check the fuel pump relay and fuse.
  4. If the pump is faulty, replace it.

4. MAF Sensor Cleaning/Replacement

• Sub-steps:
  1. Locate the MAF sensor on the air intake duct.
  2. Disconnect the wiring harness and remove the MAF sensor.
  3. Use MAF cleaner spray to clean the sensor elements; allow it to dry completely.
  4. Reinstall the MAF sensor and reconnect the wiring harness. If damaged, replace it.

5. Oxygen Sensor Inspection

• Sub-steps:
  1. Locate the upstream oxygen sensor on the exhaust manifold.
  2. Disconnect the sensor and inspect the wiring for damage.
  3. Use a multimeter to test the sensor's voltage output; replace if faulty.
  4. Reinstall a new sensor if necessary.