how to fix P0174 code on Ford F-150 12th Generation (2009-2014)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the vehicle is on a flat surface and secured with wheel chocks.

2. Inspect and Replace Vacuum Lines

• Sub-steps:
  • Visual inspection of all vacuum lines connected to the intake manifold, especially near the throttle body and bank 2.
  • Replace any damaged or cracked vacuum lines using appropriate length and size hoses.
• Tools Required: Pliers, hose cutter.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the MAF sensor with MAF cleaner spray. If heavily contaminated, replace with a new sensor.
• Tools Required: Torx or socket set, MAF cleaner.
• Safety Warning: Avoid touching the MAF sensor with fingers as oil can damage the sensor.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "on" position (do not start) and check the fuel pressure; it should meet manufacturer specifications (typically around 30-50 psi).
  • If the pressure is low, inspect and potentially replace the fuel pump or fuel filter.
• Tools Required: Fuel pressure gauge, wrench set.

5. Inspect Intake Manifold

• Sub-steps:
  • Remove the intake manifold if necessary to inspect the gaskets and seals for wear.
  • Replace any damaged gaskets or seals.
  • Reassemble the manifold ensuring all bolts are torqued to manufacturer specifications (typically around 15-20 lb-ft).
• Tools Required: Socket set, torque wrench.

6. Test Oxygen Sensors

• Sub-steps:
  • Use a multimeter to check the voltage output of the downstream oxygen sensor on bank 2.
  • If the readings are outside the normal range (0.1-0.9 volts), replace the oxygen sensor.
• Tools Required: Multimeter, socket set.