what does the P0171 code mean for my Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the negative terminal of the battery.
• Allow engine to cool down if recently running.

2. Inspect and Repair Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses and connections for cracks or damage.
  2. Tighten any loose clamps or replace damaged hoses.
  3. If leaks are found, replace the necessary components.

3. Check and Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake system.
  2. Disconnect the electrical connector and remove the sensor.
  3. Clean the MAF sensor with MAF cleaner spray; do not use other cleaners.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Test Fuel System

• Sub-steps:
  1. Attach a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "ON" position (without starting) to check fuel pressure.
  3. Compare the reading to manufacturer specifications; replace the fuel pump if pressure is low.
  4. Inspect the fuel filter and replace if clogged.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-cat) and downstream (post-cat) O2 sensors.
  2. Use a multimeter to test for proper voltage output.
  3. Replace any faulty O2 sensors.