how to fix P0171 code in Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

1. Visually inspect all vacuum hoses for cracks or disconnections.
2. Use a smoke machine or carburetor cleaner to detect leaks around the intake manifold and vacuum lines.
3. Replace any damaged hoses or gaskets found during inspection.

3. Clean or Replace Mass Airflow Sensor

1. Locate the MAF sensor on the air intake duct.
2. Disconnect the electrical connector and remove the sensor using a Torx screwdriver.
3. Clean the sensor with MAF cleaner and allow it to dry; if damaged, replace with a new sensor.
4. Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel Pressure

1. Locate the fuel pressure test port on the fuel rail.
2. Connect the fuel pressure gauge to the test port.
3. Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading; it should match specifications (usually around 50-60 psi for most models).
4. If pressure is low, check the fuel pump, filter, and regulators; replace components as necessary.

5. Inspect Fuel Injectors

1. Remove the engine cover (if applicable) to access the fuel rail.
2. Disconnect the fuel injector electrical connectors.
3. Perform a resistance check on each injector with a multimeter; replace any injectors that are out of specification.
4. Clean fuel injectors using a fuel injector cleaning kit or replace them if they are clogged.