FAULTBASE
Error CodesASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/Ford/F-150/Fourteenth Generation (2021-present)/how to diagnose P0171 code in Ford F-150 Fourteenth Generation (2021-present)

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

Ford F-150 Fourteenth Generation (2021-present)

Error Codes
Severity: highDifficulty: mediumError Code: P01712-4 hours
3 min read
544 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix P0171 lean condition in Ford F-150 (2021-present). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0171
Affected Component
Engine
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems.
  • ⚠Allow the engine to cool before inspecting any components.

Symptoms

  • •Check engine light illuminated
  • •Rough idle when the engine is warm
  • •Decrease in fuel efficiency
  • •Engine hesitation or stalling during acceleration
  • •Increased exhaust emissions

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm the P0171 code and check for any additional codes.
  2. 2Inspect the air intake system for vacuum leaks, including hoses, gaskets, and intake manifold.
  3. 3Check the fuel pressure using a fuel pressure gauge to ensure it meets manufacturer specifications.
  4. 4Inspect the Mass Air Flow (MAF) sensor for dirt or damage and clean it if necessary.
  5. 5Examine the fuel injectors for proper operation and signs of blockage or leaks.
  6. 6Review the engine's short-term and long-term fuel trim values using a scan tool to assess fuel mixture adjustments.

Solution

Solution

1. Preparation

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

2. Inspect and Repair Vacuum Leaks

  • Tools Required: Vacuum gauge, torque wrench.
  • Use a vacuum gauge to check for leaks in the intake system.
  • Inspect all vacuum hoses and connections for cracks or disconnections.
  • Tighten any loose clamps and replace damaged hoses as needed.

3. Fuel Pressure Check

  • Tools Required: Fuel pressure gauge.
  • Locate the fuel rail test port and connect the fuel pressure gauge.
  • Start the engine and observe the pressure readings. Compare them with manufacturer specifications.
  • If pressure is low, check the fuel pump and filter; replace if necessary.

4. MAF Sensor Inspection and Cleaning

  • Tools Required: MAF sensor cleaner, screwdriver.
  • Locate the MAF sensor in the air intake duct.
  • Remove the sensor and inspect for dirt or damage.
  • Clean the MAF sensor with MAF cleaner and allow it to dry before reinstalling.

5. Fuel Injector Inspection

  • Tools Required: Fuel injector cleaner, multimeter.
  • Use a multimeter to check the resistance of each fuel injector.
  • If any injector is out of spec, replace it.
  • If injectors are clogged, use a fuel injector cleaning kit or replace them.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II scanner
  • •Vacuum gauge
  • •Fuel pressure gauge
  • •MAF sensor cleaner
  • •Multimeter
  • •Screwdrivers

Parts Required

  • •Vacuum hoses (if damaged)
  • •Fuel filter (if necessary)
  • •MAF sensor (if defective)
  • •Fuel injectors (if not functioning)

Additional Information

Error Code
P0171
Affected Component
Engine
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
6 items
Parts Required
4 items

Related Faults

  1. why does my Ford F-150 battery keep dying after a few days?

    Learn how to diagnose and fix battery drain issues in Ford F-150. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Electrical6 symptoms

  2. what could cause my Ford F-150 Fourteenth Generation (2021-present) heater not to turn on?

    Learn how to diagnose and fix the heater not working in your Ford F-150. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    HVAC5 symptoms

  3. why does my Ford F-150 battery die when the car is off?

    Learn how to diagnose and fix battery drain issues in Ford F-150. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Electrical5 symptoms

  4. how to troubleshoot my Ford F-150 Fourteenth Generation (2021-present) electrical problems?

    Learn how to troubleshoot and fix electrical problems in your Ford F-150 (2021-present). Step-by-step guide with diagnostic steps and repair instructions.

    Electrical6 symptoms

  5. how to fix the power windows that won’t work in my Ford F-150?

    Learn how to diagnose and fix power windows not working in Ford F-150. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Electrical5 symptoms

  6. why does my Ford F-150 vibrate at high speeds

    Learn how to diagnose and fix vibrations at high speeds in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

    Suspension5 symptoms

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation