how can I fix the P0171 code on my Volkswagen Golf MK7.5 (2020-Present)?

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down for safety.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Socket set, screwdrivers
• Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine to detect leaks if necessary.
• Replace any damaged hoses or gaskets found during inspection.

3. Clean the Mass Air Flow (MAF) Sensor

• Tools Required: MAF cleaner spray (non-residue type)
• Locate the MAF sensor on the intake duct.
• Remove the MAF sensor using the appropriate socket.
• Spray the MAF cleaner onto the sensor elements, ensuring not to touch them directly.
• Allow the sensor to dry completely before reinstalling it.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Locate the fuel rail and connect the fuel pressure gauge.
• Turn the ignition to the "On" position without starting the engine and record the pressure.
• Compare the reading to the manufacturer specifications (typically around 50-60 psi for many models).
• If the pressure is low, inspect the fuel pump and filter for blockages and replace as needed.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit (optional), socket set
• Remove the fuel rail assembly including the injectors.
• Inspect injectors for clogs or leaks; replace if any issues are found.
• Clean the injectors using a fuel injector cleaning kit if they are dirty.