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

Solution

1. Preparation

• Gather all necessary tools and parts. Disconnect the negative terminal of the battery.
• Tools Required: OBD-II scanner, multimeter, fuel pressure gauge, socket set, vacuum gauge, and screwdrivers.

2. Inspect Air Intake System

• Remove the engine cover if applicable.
• Visually inspect all air intake hoses for cracks or disconnections.
• Use a vacuum gauge to check for vacuum leaks by connecting it to a vacuum source and monitoring the readings.
• Replace any damaged hoses or gaskets as needed.

3. Check Fuel Pressure

• Locate the fuel rail and connect the fuel pressure gauge.
• Turn the ignition key to the "ON" position (do not start the engine) and read the pressure. It should match the specifications listed in the service manual.
• If the pressure is low, check the fuel pump and fuel filter. Replace as necessary.

4. Test MAF Sensor

• Disconnect the MAF sensor connector and use a multimeter to measure the voltage output while the engine is running.
• Compare the readings to the manufacturer specifications. If readings are out of range, replace the MAF sensor.

5. Inspect Fuel Injectors

• Remove the fuel injectors from the fuel rail.
• Perform a visual inspection for any signs of leaks or clogs.
• If necessary, clean the injectors using a fuel injector cleaning kit or replace them if they are damaged.

6. Examine Oxygen Sensors

• Check the wiring and connection to the oxygen sensors for any damage.
• Use a multimeter to test the voltage output of the upstream oxygen sensor while the engine is running. Ensure it fluctuates between 0.1 and 0.9 volts as the engine operates.
• Replace the oxygen sensor if it is faulty.