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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before beginning work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, smoke machine (optional)
• Use a vacuum gauge to measure vacuum at idle. If low, inspect hoses, intake manifold, and throttle body for leaks.
• If leaks are found, replace damaged hoses or gaskets.

3. Check and Clean MAF Sensor

• Tools Required: MAF sensor cleaner or electrical cleaner
• Remove the MAF sensor from the air intake duct.
• Spray the MAF sensor with the cleaner, avoiding contact with the sensing elements.
• Allow it to dry completely before reinstalling.

4. Test and Replace Fuel Pump (if necessary)

• Tools Required: Fuel pressure gauge, socket set
• Connect the fuel pressure gauge to the fuel rail and turn the ignition on without starting the engine. Check the pressure reading against specifications (typically around 30-45 psi).
• If the pressure is low, inspect the fuel pump circuit and replace the fuel pump if needed.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaning kit, multimeter (for testing)
• Remove the fuel rail with injectors attached from the engine.
• Use a cleaning kit to clean the injectors or replace them if they are faulty.
• Reinstall the fuel rail and ensure all connections are secure.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code and other stored codes.