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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all intake hoses for cracks or loose connections.
  2. Tighten any loose clamps and replace damaged hoses as needed.
  3. Check the intake manifold gasket for leaks. If found, replace the gasket.
• Tools Required: Socket set, screwdriver, vacuum gauge (optional).

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Remove the MAF sensor from the air intake duct.
  2. Clean the sensor with MAF cleaner or replace it if damaged.
  3. Reinstall the sensor and ensure all connections are secure.
• Tools Required: Torx screwdriver, MAF cleaner.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (do not start) and check the fuel pressure.
  3. If the pressure is below specifications, inspect the fuel pump and filter for issues.
• Tools Required: Fuel pressure gauge.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the upstream oxygen sensor and disconnect its electrical connector.
  2. Use a multimeter to check the sensor's voltage output while the engine is running.
  3. Replace the sensor if it is not within the specified range (0.1-0.9 volts for a healthy sensor).
• Tools Required: O2 sensor socket, multimeter.

6. Reassemble and Test

• Reconnect all components and ensure everything is securely fastened.
• Reconnect the negative battery terminal.