how to fix P0174 code on Honda Civic 10th Generation (2016-2021)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or damage.
  2. Use a smoke machine or carburetor cleaner to locate any vacuum leaks by spraying around suspected areas and observing for RPM changes.
  3. Replace any damaged hoses or gaskets identified during the inspection.

3. Check and Clean MAF Sensor

• Sub-steps:
  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 (typically requires a Torx or Phillips screwdriver).
  4. Clean the sensor using MAF cleaner spray and allow it to dry before reinstallation.
  5. Reinstall the MAF sensor and reconnect the electrical connector.

4. Test Fuel Pressure

• Sub-steps:
  1. Locate the fuel rail and find the fuel pressure test port.
  2. Connect the fuel pressure gauge to the test port.
  3. Turn the ignition key to the "ON" position (do not start) and observe the fuel pressure reading.
  4. Compare the reading with the manufacturer's specifications (usually 40-50 psi for Honda engines).
  5. If the pressure is low, check the fuel pump, filter, and pressure regulator for faults.

5. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0174 code.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to verify that the issue is resolved and the check engine light does not reappear.