how to fix P0171 lean condition code on Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative terminal of the battery to ensure safety.
• Allow the engine to cool before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:

  1. Visually inspect all hoses and connections in the air intake system for cracks or disconnections.
  2. Use a smoke machine or carb cleaner to identify vacuum leaks while the engine is running.
  3. Replace any damaged or disconnected hoses.

• Tools Required:

  • Smoke machine (optional)
  • Carb cleaner (optional)

3. Clean or Replace MAF Sensor

• Sub-steps:

  1. Locate the MAF sensor in the air intake duct.
  2. Carefully disconnect the electrical connector.
  3. Remove the sensor using a Torx or socket set.
  4. Clean the sensor using MAF cleaner (do not touch the sensing element).
  5. If cleaning does not resolve issues, replace the MAF sensor with a new one.

• Tools Required:

  • Torx or socket set
  • MAF cleaner

4. Check and Replace Fuel Filter (if necessary)

• Sub-steps:

  1. Locate the fuel filter in the fuel line.
  2. Relieve fuel system pressure by removing the fuel pump fuse and running the engine until it stalls.
  3. Disconnect the fuel lines from the filter using a line removal tool.
  4. Replace the old fuel filter with a new one, ensuring proper orientation.

• Tools Required:

  • Fuel line removal tool

5. Test Fuel Pressure

• Sub-steps:

  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "On" position (do not start) and check the fuel pressure reading.
  3. Compare the reading to manufacturer specifications and replace the fuel pump if pressure is low.

• Tools Required:

  • Fuel pressure gauge