how to fix P0171 code in Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the engine to cool down if it has been running.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, flashlight
• Use a vacuum gauge to check for proper manifold vacuum.
• Visually inspect all vacuum lines for cracks or disconnections.
• Tighten any loose connections or replace damaged hoses.
• Inspect the intake manifold gasket for any signs of leakage and replace if necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner (specific cleaner), screwdriver set
• Carefully detach the MAF sensor from the intake duct.
• Spray MAF sensor cleaner onto the sensor element, avoiding direct contact with the wiring.
• Allow the sensor to dry completely before reinstalling.
• If cleaning does not resolve the issue, replace the MAF sensor following the manufacturer's specifications.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Attach the fuel pressure gauge to the fuel rail test port.
• Turn the ignition key to the "ON" position without starting the engine to check the pressure.
• Compare the reading to the manufacturer's specifications; it should typically be around 50-60 psi for most gasoline engines.
• If the pressure is low, inspect the fuel pump, fuel filter, and fuel lines for issues. Replace any faulty components.

5. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaning kit, basic socket set
• Remove the fuel rail to access the fuel injectors.
• Use a fuel injector cleaning kit to clean the injectors according to the instructions provided with the kit.
• Reassemble the fuel rail and recheck for leaks.