how to fix P0171 code in Volkswagen Golf MK7 (2015-2019)

Solution

1. Preparation

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

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver
• Using a vacuum gauge, check for leaks in the vacuum lines.
• If leaks are found, replace the damaged hoses or tighten any loose connections.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Remove the MAF sensor from the air intake duct by unscrewing the mounting screws.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely.
• Reinstall the MAF sensor securely.

4. Check Fuel System

• Tools Required: Fuel pressure gauge, socket set
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (without starting) and check the fuel pressure; it should be within the manufacturer's specifications.
• If pressure is low, check the fuel pump and filter. Replace as necessary.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaning kit, multimeter
• Test the fuel injectors' resistance with a multimeter; it should be within the specified range.
• If they are out of spec, consider cleaning or replacing the injectors.

6. Replace Oxygen Sensors (if necessary)

• Tools Required: Oxygen sensor socket, wrench
• If the oxygen sensors are found to be faulty, replace them.
• Ensure the new sensors are properly connected and secured.