how to fix P0171 code on my Volkswagen Golf MK7 (2015-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, vacuum gauge, fuel pressure gauge, MAF sensor cleaner, basic hand tools, torque wrench.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect the Intake System

• Remove the engine cover if applicable.
• Visually inspect all vacuum hoses for cracks or disconnections.
• Use a vacuum gauge to check for any leaks in the intake system. If a leak is found, replace the damaged hose or seal.

3. Clean the MAF Sensor

• Locate the MAF sensor in the air intake system.
• Disconnect the electrical connector from the MAF sensor.
• Remove the MAF sensor using appropriate tools.
• Spray MAF sensor cleaner onto the sensor elements, avoiding physical contact.
• Allow the sensor to dry completely before reinstalling it.

4. Check Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail's test port.
• Turn the ignition to the "ON" position without starting the engine to check the fuel pressure.
• Compare the reading to manufacturer specifications (usually between 50-60 psi for most engines).
• If the pressure is low, inspect the fuel pump and fuel filter; replace as necessary.

5. Inspect Fuel Injectors

• Remove the fuel rail with the injectors still attached.
• Visually inspect the injectors for clogs or leaks.
• If necessary, clean the injectors using a dedicated fuel injector cleaner or replace them if damaged.

6. Reassemble and Reconnect

• Reinstall the fuel rail and ensure all connections are secure.
• Reconnect the MAF sensor and any electrical connectors.
• Reconnect the battery.
• Clear any stored codes using the OBD-II scanner.