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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shock.
• Allow the engine to cool down before beginning work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake duct for cracks or loose clamps.
  2. Tighten any loose connections and replace any damaged hoses.
  3. Use a smoke machine to check for unmetered air leaks if necessary.

3. Clean MAF Sensor

• Tools Required: MAF sensor cleaner
• Sub-steps:
  1. Locate the MAF sensor in the air intake path.
  2. Disconnect the electrical connector and remove the MAF sensor.
  3. Spray the sensor with MAF cleaner and let it dry completely before reinstallation.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Sub-steps:
  1. Locate the fuel rail and connect the fuel pressure gauge.
  2. Turn the ignition to the ON position without starting the engine to check the pressure.
  3. Compare the reading to the manufacturer specifications (usually around 40-50 psi).
  4. If the pressure is low, inspect the fuel pump and filter for issues.

5. Inspect and Replace Oxygen Sensor (if necessary)

• Tools Required: O2 sensor socket
• Sub-steps:
  1. Locate the upstream oxygen sensor on the exhaust manifold.
  2. Disconnect the electrical connector and remove the sensor using the O2 sensor socket.
  3. Install the new oxygen sensor, ensuring the threads are clean and properly torqued.
  4. Reconnect the electrical connector.