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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool down before beginning work.

2. Inspect and Repair Intake System

• Tools Required: Socket set, vacuum gauge, flashlight
• Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• If any hoses are damaged, replace them with OEM-spec hoses.
• Check the intake manifold gasket for leaks; replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, Torx screwdriver
• Remove the MAF sensor from the intake duct.
• Clean the sensor with MAF cleaner; do not touch the sensor element.
• If cleaning does not resolve the issue, replace the MAF sensor with a new unit.

4. Test Fuel System

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position (do not start the engine) and check the pressure reading against the manufacturer's specifications.
• If the pressure is low, inspect the fuel pump, filter, and regulator, replacing any faulty components.

5. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench
• Locate the upstream (pre-catalytic converter) oxygen sensor.
• Remove the sensor using the O2 sensor socket.
• Install a new oxygen sensor, ensuring it is properly tightened per manufacturer's torque specifications.