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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent any electrical shorts.
• Allow the engine to cool.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver, flashlight
• Visually inspect all vacuum hoses for cracks or disconnections.
• Use a vacuum gauge to check for proper readings; any significant deviation may indicate a leak.
• Tighten or replace any loose or damaged hoses as needed.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, Torx screwdriver
• Remove the MAF sensor from the air intake tube.
• Use MAF cleaner to spray the sensor elements gently; do not touch them with your fingers.
• Allow the sensor to dry completely before reinstalling.
• If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Test Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start the engine) and check the fuel pressure; it should meet manufacturer specifications.
• If the pressure is low, inspect the fuel pump and filter. Replace as necessary.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket
• Locate the upstream oxygen sensor (pre-catalytic converter).
• Remove the sensor using an O2 sensor socket.
• Inspect the sensor for damage or contamination. Replace if necessary.

6. Clear Codes and Reconnect Battery

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code from the system.