how to diagnose P0171 code on Honda Civic 11th Generation (2022-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect the air intake ducts, hoses, and clamps for any signs of damage or disconnection.
  • If any leaks are found, replace the damaged components (e.g., hoses or clamps).
  • Replace the air filter if it is dirty or clogged.

Tools Required:

• Socket set
• Screwdrivers

3. Check and Clean MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake path.
  • Remove the electrical connector and unbolt the sensor.
  • Clean the MAF sensor using MAF cleaner spray, ensuring not to touch the sensing element.
  • Reinstall the MAF sensor and reconnect the electrical connector.

Tools Required:

• Torx or socket set
• MAF sensor cleaner

4. Test and Adjust Fuel System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail and turn the ignition to the ON position without starting the engine.
  • Check the fuel pressure reading against Honda specifications (typically around 40-50 psi).
  • If pressure is low, inspect the fuel pump, fuel filter, and fuel injectors for proper operation. Replace any faulty components.

Tools Required:

• Fuel pressure gauge
• Socket set

5. Inspect Oxygen Sensors

• Sub-steps:
  • Locate the upstream (pre-catalytic converter) oxygen sensor.
  • Use a multimeter to check voltage output (should fluctuate between 0.1 to 0.9 volts).
  • If the sensor is faulty, replace it with a new one.

Tools Required:

• O2 sensor socket
• Multimeter