why does my Ford F-150 Fourteenth Generation (2021-present) have a check engine light and code P0171

Learn how to diagnose and fix P0171 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 electrical shorts.
• Allow the engine to cool before beginning work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Remove the air intake duct by loosening the clamps and disconnecting any electrical connectors.
  2. Visually inspect the duct for cracks or loose fittings.
  3. Replace any damaged components.
  4. Reinstall the duct securely.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake path.
  2. Disconnect the electrical connector and unscrew the MAF sensor.
  3. Clean the sensor using MAF cleaner and a soft cloth. If damaged, replace it with a new sensor.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Start the engine and monitor the pressure; it should match manufacturer specifications (refer to the service manual).
  3. If pressure is low, inspect the fuel pump and fuel filter for issues. Replace as necessary.

5. Inspect and Repair Vacuum Lines

• Sub-steps:
  1. Inspect all vacuum hoses for cracks or disconnections.
  2. Replace any damaged hoses with new ones.
  3. Ensure all connections are secure and leak-free.

6. Test Fuel Injectors

• Sub-steps:
  1. Use an injector tester to verify each fuel injector is functioning correctly.
  2. Replace any faulty injectors with OEM parts.