how to fix P0174 code on Ford F-150 Fourteenth Generation (2021-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect and Repair Vacuum Leaks

1. Visually inspect all vacuum lines and connections for cracks or disconnections.
2. Use a smoke machine or carburetor cleaner to locate any leaks in hoses or gaskets.
3. Replace any damaged hoses or gaskets.
4. Reconnect any disconnected hoses.

3. Clean or Replace MAF Sensor

1. Locate the MAF sensor in the air intake duct.
2. Disconnect the electrical connector from the MAF sensor.
3. Remove the MAF sensor from the duct (usually requires a Torx or Phillips screwdriver).
4. Use MAF cleaner to gently clean the sensor elements. Allow it to dry completely.
5. Reinstall the sensor and reconnect the electrical connector.

4. Test and Repair Fuel System

1. Connect a fuel pressure gauge to the fuel rail’s test port.
2. Turn the ignition to the "ON" position (without starting the engine) and check the fuel pressure reading.
3. Compare the reading to the specifications in the service manual (usually around 30-50 psi for the F-150).
4. If the pressure is low, check fuel pump relay and fuse; replace the fuel pump if necessary.
5. If injectors are faulty, remove and replace them using the appropriate tools.

5. Recheck O2 Sensor Functionality

1. Locate the downstream oxygen sensor on bank two.
2. Use a multimeter to check the voltage output of the sensor while the engine is running (should fluctuate between 0.1 to 0.9 volts).
3. If the sensor is not functioning correctly, replace it.