how to fix P0171 lean condition code on Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, and replacement hoses if needed.
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use a vacuum gauge to test the intake for leaks.
  • Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner, screwdriver set.
  • Remove the MAF sensor from the air intake duct.
  • Spray MAF cleaner onto the sensor and allow it to dry completely.
  • Reinstall the sensor securely.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge.
  • Attach the fuel pressure gauge to the fuel rail.
  • Start the engine and check the fuel pressure reading.
  • If pressure is below specifications, check the fuel pump and filter for issues.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaning kit or replacement injectors.
  • Remove the fuel injectors from the fuel rail.
  • Inspect for clogs and clean using a fuel injector cleaning kit.
  • Replace any faulty injectors if cleaning does not resolve the issue.

6. Verify Oxygen Sensor Functionality

• Tools Required: Multimeter.
  • Disconnect the upstream oxygen sensor.
  • Use a multimeter to test the sensor's voltage output while the engine is running.
  • Replace the oxygen sensor if it does not meet manufacturer specifications.