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

Solution

1. Preparation

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

2. Inspect and Repair Intake System

• Inspect Hoses and Connections:
  • Check all vacuum hoses, intake ducts, and connections for cracks or disconnections.
  • Tighten any loose clamps.
• Replace Damaged Components:
  • If any hoses or clamps are damaged, replace them with OEM parts.

3. Clean or Replace MAF Sensor

• Remove MAF Sensor:
  • Locate the MAF sensor in the intake duct.
  • Disconnect the electrical connector and remove the sensor using a Torx screwdriver.
• Clean MAF Sensor:
  • Use MAF sensor cleaner and a soft brush to clean the sensor element.
  • Allow the sensor to dry completely before reinstalling.
• Reinstall MAF Sensor:
  • Secure the MAF sensor back in place and reconnect the electrical connector.

4. Check and Replace Fuel Filter (if necessary)

• Locate Fuel Filter:
  • Refer to the service manual for the precise location of the fuel filter.
• Remove Fuel Lines:
  • Use a line wrench to disconnect the fuel lines from the filter, ensuring to catch any spilled fuel with a rag.
• Replace Fuel Filter:
  • Install the new fuel filter, ensuring the directional flow is correct.
  • Reconnect the fuel lines securely.

5. Test Fuel Pressure

• Connect Fuel Pressure Gauge:
  • Attach the gauge to the fuel rail service port.
• Check Fuel Pressure:
  • Turn the ignition to the "ON" position (do not start) and observe the pressure reading.
  • Compare the reading to the specifications in the service manual. Replace the fuel pump if pressure is below specs.

6. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0171 code from the ECM.
• Take the vehicle for a test drive to monitor performance and check for code reappearance.