my Honda Civic 10th Generation (2016-2021) has a check engine light and code P0171, what’s the fix

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, torque wrench, vacuum gauge.
• Check all vacuum lines connected to the intake manifold for cracks or disconnections.
• Tighten any loose clamps or connections. Replace any damaged hoses.
• If the intake manifold gasket is leaking, remove the intake manifold and replace the gasket.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver, torque wrench.
• Remove the MAF sensor from the air intake duct.
• Clean the MAF sensor with MAF sensor cleaner following the manufacturer's instructions.
• Reinstall the sensor and ensure all connections are secure.

4. Check Fuel Pressure and Injectors

• Tools Required: Fuel pressure gauge, multimeter (for injector testing).
• Connect the fuel pressure gauge to the fuel rail and turn the ignition to the ON position without starting the engine.
• Verify that the fuel pressure is within the manufacturer's specified range (typically 40-50 psi).
• If the pressure is low, inspect the fuel pump and filter for issues.
• Test the fuel injectors with a multimeter to ensure they are receiving the correct voltage and functioning properly.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench.
• Locate the upstream O2 sensor and inspect the wiring for damage.
• If necessary, replace the O2 sensor with a new one, ensuring it is tightened to the manufacturer's torque specifications.