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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect for Vacuum Leaks

• Visually check all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine or carburetor cleaner around the intake areas to detect any leaks.
• Repair or replace any damaged hoses or seals.

3. Check Fuel Pressure

• Locate the fuel pressure test port on the fuel rail.
• Connect a fuel pressure gauge and turn the ignition to the "ON" position (do not start the engine).
• Check the fuel pressure reading; it should be within the manufacturer's specified range (typically 40-50 psi).
• If pressure is low, consider replacing the fuel pump or fuel filter.

4. Clean MAF Sensor

• Locate the MAF sensor, typically found in the air intake duct.
• Disconnect the electrical connector and unscrew the sensor from the duct.
• Use MAF sensor cleaner to clean the sensor element carefully.
• Allow it to dry completely before reinstalling.

5. Inspect Fuel Injectors

• Remove the fuel rail to access the injectors.
• Inspect injectors for signs of clogging or leakage.
• If necessary, clean the injectors using a professional fuel injector cleaning kit or replace them if they are faulty.

6. Replace ECT Sensor (if necessary)

• Locate the engine coolant temperature sensor, usually near the thermostat housing.
• Disconnect the electrical connector and remove the sensor using a socket.
• Install the new sensor with the specified torque and reconnect the electrical connector.