how to fix P0171 code on my Volkswagen Golf MK7.5 (2020-Present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, or new hoses
• Inspect all vacuum lines and connections for cracks or disconnections.
• Replace any damaged hoses and ensure all connections are secure.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner
• Remove the MAF sensor from the air intake.
• Spray the sensor with MAF cleaner and let it dry completely before reinstalling.
• If the sensor is damaged, replace it with a new one.

4. Test and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start the engine) and record the pressure reading; it should match manufacturer specifications (usually around 50-60 psi for most VW engines).
• If the pressure is low, check the fuel pump and filter for clogs or failure.

5. Inspect and Clean Fuel Injectors

• Tools Required: Injector cleaning kit or replacement injectors
• If injectors are clogged, use an injector cleaning kit to clean them or replace them if necessary.

6. Verify ECT Sensor Functionality

• Tools Required: Multimeter
• Disconnect the ECT sensor and test its resistance against manufacturer specifications. Replace if out of spec.

7. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code and any other stored codes.