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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, flashlight.
• Using a vacuum gauge, check for proper vacuum levels.
• Inspect all vacuum hoses for cracks or disconnections. Replace any damaged hoses.
• Check the intake manifold gasket for leaks; replace if necessary.

3. Fuel Pressure Check

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the “ON” position (without starting) to check the pressure. Compare with the manufacturer’s specifications (typically around 40-50 psi).
• If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockage.

4. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or isopropyl alcohol, soft cloth.
• Disconnect the MAF sensor plug.
• Remove the MAF sensor from the intake duct.
• Clean the sensor wires gently with MAF cleaner. Allow it to dry completely before reinstalling.
• If damaged, replace the MAF sensor with a new one.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket.
• Locate the upstream oxygen sensor and check for corrosion or damage.
• Using the O2 sensor socket, remove the sensor and inspect its condition.
• Replace the sensor if it is faulty or if the readings are out of specification when tested.

6. Check and Replace ECT Sensor (if necessary)

• Tools Required: Socket set, coolant.
• Locate the ECT sensor, usually near the thermostat housing.
• Disconnect the electrical connector and remove the sensor.
• Replace with a new sensor and refill the cooling system as necessary.