how to diagnose P0171 code on my Ford F-150 Fourteenth Generation (2021-present)

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

Solution

1. Preparation

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

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Check all vacuum hoses and connections for cracks or disconnections; replace any damaged hoses.
  2. Inspect the intake manifold gasket for leaks and replace if necessary.
  3. Clean the throttle body using throttle body cleaner and a soft cloth.

3. Check and Clean MAF Sensor

• Sub-steps:
  1. Carefully remove the MAF sensor from the air intake duct.
  2. Spray MAF sensor cleaner on the sensor elements and allow it to dry completely before reinstalling.
  3. Reconnect the MAF sensor and ensure all connections are secure.

4. Inspect Fuel System

• Sub-steps:
  1. Use a fuel pressure gauge to check the fuel pressure; it should be within the manufacturer’s specified range.
  2. If pressure is low, inspect the fuel pump and replace the fuel filter if clogged.
  3. Consider testing fuel injectors for proper operation and cleaning them if necessary.

5. Check Exhaust System

• Sub-steps:
  1. Inspect the exhaust manifold and pipes for leaks, especially at joints and connections.
  2. Repair any leaks found in the exhaust system.

6. Replace ECT Sensor (if needed)

• Sub-steps:
  1. Locate the ECT sensor and disconnect the electrical connector.
  2. Unscrew the sensor using appropriate tools and replace it with a new one.
  3. Reconnect the electrical connector securely.