how to fix P0171 code in Honda Civic 9th Generation (2012-2015)

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery cable to avoid electrical shorts.
• Gather tools and parts needed for the repair.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect the air intake hose and connections for cracks or loose clamps.
  • Tighten or replace any damaged hoses or clamps.
  • Clean the throttle body using throttle body cleaner to ensure proper airflow.

3. Check and Clean MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Disconnect the electrical connector from the MAF sensor.
  • Remove the MAF sensor using a screwdriver.
  • Clean the MAF sensor with MAF cleaner spray and allow it to dry before reinstalling.
  • Reinstall the MAF sensor and reconnect the electrical connector.

4. Inspect Fuel System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail test port and check for proper fuel pressure (refer to service manual for specifications).
  • If fuel pressure is low, inspect the fuel filter for clogs and replace if necessary.
  • Test the fuel pump for proper operation and replace if faulty.

5. Check Oxygen Sensor

• Sub-steps:
  • Locate the upstream oxygen sensor (before the catalytic converter).
  • Disconnect the oxygen sensor's electrical connector.
  • Use a wrench to remove the oxygen sensor from the exhaust manifold.
  • Inspect the sensor for contamination; replace if necessary.
  • Install the new sensor and reconnect the electrical connector.

6. Check for Vacuum Leaks

• Sub-steps:
  • Inspect all vacuum lines connected to the intake manifold for cracks or disconnections.
  • Use a smoke machine or carburetor cleaner to find leaks by spraying around suspected areas while the engine is running.
  • Repair or replace any damaged vacuum lines.