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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, socket set
• Instructions:
  1. Use a vacuum gauge to check for leaks in the intake system.
  2. Visually inspect all vacuum hoses and connectors for damage or disconnection.
  3. Replace any damaged hoses or gaskets.
  4. Reconnect all hoses securely.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Instructions:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and unscrew the sensor from its housing.
  3. Spray MAF sensor cleaner on the sensor element and allow it to dry completely.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel System

• Tools Required: Fuel pressure gauge, multimeter
• Instructions:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition key to the "on" position to check fuel pressure; it should meet manufacturer specifications (typically around 50-60 psi).
  3. If pressure is low, inspect the fuel pump and fuel filter for issues, replacing as necessary.

5. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench
• Instructions:
  1. Locate the upstream oxygen sensor on the exhaust manifold.
  2. Use an O2 sensor socket to remove the sensor.
  3. Inspect the sensor for contamination or damage; replace if necessary.
  4. Install the new sensor and torque it to manufacturer specifications (usually 30-40 ft-lbs).

6. Throttle Body Cleaning

• Tools Required: Throttle body cleaner, soft brush
• Instructions:
  1. Remove the air intake duct to access the throttle body.
  2. Spray throttle body cleaner inside the throttle body and use a soft brush to remove carbon deposits.
  3. Reassemble the intake duct and ensure all connections are secure.