how to fix P0171 code on Ford F-150 12th Generation (2009-2014)

Learn how to diagnose and fix P0171 engine too lean condition in Ford F-150 12th Generation. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers, vacuum gauge
• Remove the air intake ducting and inspect for damage or loose connections.
• Tighten any loose clamps and replace any damaged hoses.
• Reinstall the ducting securely.

3. Check and Replace Vacuum Lines

• Tools Required: Pliers, replacement vacuum lines
• Inspect all vacuum lines for wear and tear.
• Replace any damaged or cracked vacuum hoses with new ones.
• Ensure all connections are secure.

4. Fuel Pressure Test

• Tools Required: Fuel pressure gauge
• Locate the fuel rail test port and connect the fuel pressure gauge.
• Start the engine and check the fuel pressure reading against the manufacturer's specifications (usually around 30-40 psi for most Ford engines).
• If the pressure is low, consider replacing the fuel pump or checking the fuel filter for clogs.

5. Clean MAF Sensor

• Tools Required: MAF sensor cleaner
• Remove the MAF sensor from its housing.
• Spray the MAF sensor with the cleaner and allow it to dry completely.
• Reinstall the MAF sensor carefully.

6. Test Fuel Injectors

• Tools Required: Multimeter, injector cleaning kit (if necessary)
• Use a multimeter to check for proper resistance across the fuel injectors.
• If any injectors show abnormal resistance or fail to click when activated, replace them.
• If injectors are clogged, use an injector cleaning kit to clean them.