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

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, socket set, MAF cleaner, torque wrench, safety glasses, gloves.
• Safety Warnings: Disconnect the battery before working on electrical systems; allow the engine to cool before starting repairs.

2. Inspect and Replace Vacuum Hoses

1. Visually inspect all vacuum hoses connected to the intake manifold.
2. If any hoses are damaged, replace them with OEM parts.
3. Ensure all connections are tight to prevent air leaks.

3. Clean or Replace MAF Sensor

1. Locate the MAF sensor on the air intake duct.
2. Disconnect the electrical connector.
3. Remove the sensor from the duct using a socket set.
4. Spray MAF cleaner onto the sensor element and let it dry completely.
5. Reinstall the sensor and reconnect the electrical connector.

4. Test Fuel Pressure

1. Locate the fuel pressure test port on the fuel rail.
2. Connect a fuel pressure gauge to the test port.
3. Turn the ignition to the "ON" position without starting the engine and observe the fuel pressure reading. It should match manufacturer specifications (typically around 40-50 psi).
4. If the pressure is low, inspect the fuel pump and filter for issues.

5. Inspect Intake Manifold Gasket

1. Remove any components obstructing access to the intake manifold.
2. Inspect the intake manifold gasket for cracks or leaks.
3. If damaged, replace the gasket and torque it to the manufacturer's specifications.

6. Clear Codes and Test Drive

1. Use the OBD-II scanner to clear the P0171 code.
2. Test drive the vehicle under various conditions to ensure the issue is resolved.