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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Inspect Air Intake System

• Tools Required: Screwdriver set, vacuum gauge
• Remove the air intake duct and visually inspect for cracks or broken hoses.
• Replace any damaged components.
• Reattach the air intake duct and ensure all clamps are secure.

3. Clean Mass Air Flow (MAF) Sensor

• Tools Required: MAF cleaner (specific cleaner for MAF sensors)
• Locate the MAF sensor in the air intake system.
• Disconnect the electrical connector and remove the sensor.
• Spray the MAF cleaner onto the sensing elements and let it dry completely.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge
• Locate the fuel rail and connect the fuel pressure gauge.
• Turn the ignition on (do not start the engine) to check the pressure.
• Compare the reading with the manufacturer specifications (usually 40-50 psi).
• If the pressure is low, check the fuel pump and filter for faults.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket
• Locate the upstream oxygen sensor (before the catalytic converter).
• Disconnect the electrical connector and remove the sensor using an O2 sensor socket.
• Inspect the sensor for contamination or damage and replace if necessary.
• Reinstall the new or cleaned sensor and reconnect the electrical connector.

6. Reassemble and Reset Codes

• Reconnect the battery terminal.
• Start the engine and allow it to reach operating temperature.
• Use the OBD-II scanner to clear the P0171 code and check for any reoccurrence.