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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Repair Vacuum Leaks

• Inspect all vacuum hoses for cracks or disconnections.
• Replace any damaged hoses.
• Use a smoke test if needed to detect leaks in the intake manifold.

3. Fuel System Check

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition to the "On" position (do not start the engine) and check the fuel pressure reading against the manufacturer’s specifications (typically 40-50 psi).
• If pressure is low, inspect the fuel pump and filter; replace if necessary.

4. Clean the MAF Sensor

• Remove the air intake duct to access the MAF sensor.
• Use MAF cleaner to spray the sensor gently; avoid touching the sensor element.
• Allow it to dry completely before reassembly.

5. Inspect and Clean Fuel Injectors

• If the injectors are dirty, use a fuel injector cleaner or remove them for professional cleaning.
• Reinstall them ensuring they are seated correctly.

6. Reassemble and Test

• Reconnect all components removed during inspection.
• Reconnect the negative battery terminal.
• Start the engine and let it idle for 5-10 minutes.