how to fix P0171 code in Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the engine is off and cool.
• Disconnect the negative battery terminal.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the intake hoses for cracks or loose connections.
  2. Tighten any loose clamps and replace damaged hoses as necessary.
  3. Check the intake manifold gasket for leaks and replace if needed.

3. Clean or Replace 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 sensor using a Torx or Phillips screwdriver.
  4. Clean the sensor with MAF cleaner spray (do not touch the sensor element) or replace it if damaged.
  5. Reinstall the sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition key to the "ON" position (do not start the engine) and check the fuel pressure reading.
  3. If the pressure is below specification (typically around 43-55 psi for Honda Civic), check the fuel pump and filter.
  4. Replace the fuel pump or filter if necessary.

5. Inspect for Vacuum Leaks

• Sub-steps:
  1. Use a smoke machine or vacuum gauge to check for leaks in the vacuum system.
  2. Locate and repair any leaks found in hoses or gaskets.
  3. Recheck the idle and performance after repairs.