how to deal with P0171 lean code on my Volkswagen Golf Seventh Generation (2013-2020)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, and a socket set.
• Sub-steps:
  1. Start the engine and listen for any hissing sounds that indicate a vacuum leak.
  2. Use a vacuum gauge to test the intake vacuum; low readings may indicate a leak.
  3. Inspect all hoses and gaskets that connect to the intake manifold. Replace any damaged hoses or gaskets.
  4. Tighten any loose clamps or connections.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner.
• Sub-steps:
  1. Locate the MAF sensor in the intake duct.
  2. Disconnect the electrical connector and remove the sensor from the duct.
  3. Spray MAF sensor cleaner onto the sensor element; do not touch it with your fingers.
  4. Allow the sensor to dry and reinstall it.

4. Check and Repair Fuel System

• Tools Required: Fuel pressure gauge and a socket set.
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the ON position without starting the engine to check initial fuel pressure.
  3. Compare the reading to the manufacturer’s specifications; typically, it should be around 50-60 psi.
  4. If pressure is low, inspect the fuel pump and filter for issues, replacing them as necessary.
  5. Test the fuel injectors for flow and operation, replacing any faulty injectors.

5. Verify Oxygen Sensor Operation

• Tools Required: Multimeter.
• Sub-steps:
  1. Locate the upstream oxygen sensor and disconnect it.
  2. Use a multimeter to test the sensor's voltage output while the engine is running.
  3. Refer to specifications; the voltage should fluctuate between 0.1 to 0.9 volts.
  4. Replace the sensor if outputs are outside this range.