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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, flashlight, socket set
• Visually inspect all vacuum hoses and connections for cracks or disconnections.
• Use a vacuum gauge to test for leaks. If present, replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, Torx screwdriver
• Remove the MAF sensor from the intake manifold.
• Spray MAF cleaner on the sensor elements and let it dry completely.
• Reinstall the sensor, ensuring it is securely connected.

4. Inspect Fuel System

• Tools Required: Fuel pressure gauge
• Connect a fuel pressure gauge to the fuel rail.
• Start the engine and check for proper fuel pressure (refer to the service manual for specific values).
• If the pressure is low, check the fuel pump and fuel filter. Replace as necessary.

5. Clean Throttle Body

• Tools Required: Throttle body cleaner, screwdriver
• Remove the air intake duct from the throttle body.
• Spray throttle body cleaner inside the throttle body and wipe clean with a lint-free cloth.
• Reinstall the air intake duct.