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how to resolve P0171 and P0174 lean codes on Ford F-150 Fourteenth Generation (2021-present) - Ford F-150
Home/Cars/Ford/F-150/Fourteenth Generation (2021-present)/how to resolve P0171 and P0174 lean codes on Ford F-150 Fourteenth Generation (2021-present)

how to resolve P0171 and P0174 lean codes on Ford F-150 Fourteenth Generation (2021-present)

Ford F-150 Fourteenth Generation (2021-present)

Error Codes
2-4 hours
Time
medium
Difficulty
high
Severity
Error Code: P0171, P0174
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
3 min read
564 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 and P0174 lean codes in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0171, P0174
Affected Component
Engine
Estimated Time
2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

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

Symptoms

  • •Check engine light illuminated
  • •Rough idle or stalling
  • •Loss of power during acceleration
  • •Poor fuel economy
  • •Increased emissions

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

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
  • •Screwdriver set
  • •Pliers
  • •Fuel pressure gauge
  • •Torx or socket set
  • •MAF cleaner

Parts Required

  • •MAF sensor (if needed)
  • •Vacuum hoses (if needed)
  • •Fuel filter (if needed)

Additional Information

Error Code
P0171, P0174
Affected Component
Engine
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
6 items
Parts Required
3 items

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Solution
1. Preparation
  • Gather necessary tools and parts.
  • Disconnect the battery to ensure safety while working on electrical components.
2. Inspect and Repair Air Intake System
  • Sub-steps:
    1. Visually inspect the air intake duct for cracks or loose fittings.
    2. Tighten any loose clamps or connections.
    3. Replace any damaged components in the air intake system.
  • Tools Required: Screwdriver set, pliers.
3. Check and Clean MAF Sensor
  • Sub-steps:
    1. Locate the MAF sensor, typically found between the air filter and throttle body.
    2. Disconnect the electrical connector from the MAF sensor.
    3. Remove the sensor using the appropriate socket.
    4. Clean the MAF sensor with MAF sensor cleaner and let it dry.
    5. Reinstall the sensor and reconnect the electrical connector.
  • Tools Required: Torx or socket set, MAF cleaner.
4. Inspect Fuel System
  • Sub-steps:
    1. Locate the fuel pressure test port on the fuel rail.
    2. Attach the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
    3. Record the fuel pressure; it should be within manufacturer specifications.
    4. If the pressure is low, check the fuel pump and fuel filter for issues.
  • Tools Required: Fuel pressure gauge.
5. Inspect Vacuum Lines
  • Sub-steps:
    1. Visually inspect all vacuum hoses for signs of wear, cracks, or disconnections.
    2. Replace any damaged hoses.
    3. Ensure all connections are secure and tight.
  • Tools Required: Visual inspection, possibly a vacuum gauge.
6. Clear Codes and Test Drive
  • Sub-steps:
    1. Use the OBD-II scanner to clear the error codes.
    2. Take the vehicle for a test drive under various conditions.
    3. Monitor for any recurrence of the P0171 or P0174 codes.
  • Tools Required: OBD-II scanner.