my Volkswagen Golf MK6 (2009-2014) gives me a P0171 lean code how to fix

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.
• Allow the engine to cool if it has been running.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use a smoke machine or carburetor cleaner to identify leaks by applying it around suspected areas while the engine is running.
  • Replace any damaged hoses or connections with OEM parts.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the air intake duct.
  • Disconnect the electrical connector and remove the MAF sensor from the housing.
  • Clean the sensor with MAF cleaner (do not use other cleaners).
  • If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Inspect Fuel System

• Sub-steps:
  • Check the fuel pump operation by listening for the pump's sound when the ignition is turned on.
  • Replace the fuel filter if it has not been changed per the maintenance schedule.
  • Use a fuel pressure gauge to check if the pressure is within the manufacturer's specifications (typically around 50-60 psi for the Golf MK6).
  • If the pressure is low, replace the fuel pump.

5. Check Engine Coolant Temperature Sensor

• Sub-steps:
  • Locate the engine coolant temperature sensor.
  • Disconnect the sensor and test it with a multimeter for resistance according to manufacturer specifications.
  • Replace the sensor if it is out of specification.