what does it mean if my Volkswagen Golf MK7 (2015-2019) has a P0171 code

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers, vacuum gauge
• Visually inspect all vacuum hoses and the intake manifold for any cracks or disconnections. Replace any damaged hoses.
• Use a vacuum gauge to test for leaks in the intake system. Repair any identified leaks.

3. Check and Clean MAF Sensor

• Tools Required: MAF sensor cleaner (spray), soft cloth
• Disconnect the electrical connector from the MAF sensor.
• Remove the MAF sensor from the intake system.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely before reinstalling.

4. Fuel System Check

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start the engine) and check the fuel pressure. It should meet the manufacturer’s specifications (typically around 55-62 psi for most models).
• If the pressure is low, check the fuel pump and filter for issues and replace if necessary.

5. Inspect Fuel Injectors

• Tools Required: Injector cleaner, socket set
• Remove the fuel injectors from the rail.
• Inspect for clogs or leaks and clean them with an appropriate injector cleaner.
• Reinstall or replace any defective injectors.