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

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, multimeter, vacuum gauge, basic hand tools (sockets, wrenches).
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery cable to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum lines for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to test for leaks around gaskets and hoses.
  3. If leaks are found, replace damaged hoses or gaskets as necessary.

3. Test Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge to the test port.
  3. Turn the ignition key to the "ON" position (do not start the engine) and check the reading.
  4. If the pressure is below specifications (consult the service manual), check the fuel pump and filter. Replace if necessary.

4. Clean or Replace MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor connector.
  2. Remove the MAF sensor from the intake duct.
  3. Clean the sensor with MAF sensor cleaner; do not touch the sensing elements.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the engine cover (if applicable) and locate the fuel injectors.
  2. Visually inspect the injectors for signs of leaking or clogging.
  3. If clogs are suspected, use a fuel injector cleaning kit or replace the injectors.

6. Check Engine Coolant Temperature Sensor

• Sub-steps:
  1. Locate the engine coolant temperature sensor and disconnect it.
  2. Use a multimeter to measure resistance and compare it with specifications in the service manual.
  3. Replace the sensor if it is out of specifications.