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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down completely before starting any work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, socket set.
• Use a vacuum gauge to check for leaks in the intake manifold and vacuum hoses.
• If leaks are found, replace damaged hoses or seals.
• Reattach all hoses securely to avoid further leaks.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver set.
• Disconnect the MAF sensor electrical connector.
• Remove the MAF sensor from the air intake duct.
• Spray the sensor with MAF cleaner and allow it to dry completely.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel Delivery

• Tools Required: Fuel pressure gauge, socket set.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start the engine) and check the fuel pressure.
• If the pressure is below specifications, inspect the fuel pump and filter for issues and replace if necessary.

5. Inspect and Replace O2 Sensors (if necessary)

• Tools Required: O2 sensor socket, torque wrench.
• Locate the upstream O2 sensor and disconnect its electrical connector.
• Use the O2 sensor socket to remove the sensor from the exhaust manifold.
• Install the new sensor with proper torque specifications (typically around 30 lb-ft).
• Reconnect the electrical connector.

6. Reset the Check Engine Light

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code and reset the check engine light.
• Perform a test drive to ensure the issue is resolved.