how to fix my Ford F-150 that has a check engine light on with 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 tools and ensure safety equipment is available.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting any work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers
• Visually inspect all hoses connected to the air intake system.
• Tighten or replace any loose or damaged hoses.
• Check the air filter; replace it if dirty.

3. Clean MAF Sensor

• Tools Required: MAF cleaner spray
• Remove the MAF sensor from the intake duct.
• Spray the MAF cleaner on the sensor element and allow it to dry completely before reinstallation.

4. Check Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine and check the fuel pressure; it should be within the manufacturer's specifications.
• If pressure is low, inspect the fuel filter and replace it if necessary.

5. Inspect and Clean Fuel Injectors

• Tools Required: Injector cleaning kit (if necessary)
• Remove the fuel injectors from the fuel rail.
• Clean the injectors using an ultrasonic cleaner or replace them if they are faulty.

6. Test Drive and Monitor

• Reconnect the battery and start the engine.
• Allow the engine to reach operating temperature and check for any error codes again. Clear the previous code if no new codes appear.