what causes the P0171 code in Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal.

2. Inspect and Repair Air Intake System

• Tools Required: Screwdrivers, pliers, flashlight
• Inspect all intake hoses and connections for signs of wear or damage.
• Replace any damaged hoses or connections as necessary.
• Ensure the air filter is clean and properly installed.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Disconnect the MAF sensor electrical connector and remove it from the intake.
• Clean the MAF sensor with MAF cleaner; do not touch the sensor element.
• Reinstall the MAF sensor or replace it if it is faulty.

4. Check Fuel System

• Tools Required: Fuel pressure gauge, wrench
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition on and check the fuel pressure; it should meet the manufacturer's specifications.
• If pressure is low, inspect or replace the fuel pump and fuel filter.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket, wrench
• Locate the upstream oxygen sensor and check its wiring for damage.
• Use a multimeter to test the sensor’s voltage output; replace if faulty.

6. Final Assembly

• Reconnect all components and hoses that were removed during the inspection.
• Reconnect the negative battery terminal.
• Start the engine and let it idle to ensure everything is functioning correctly.