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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool if it has been recently running.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, socket set, screwdriver set.
• Inspect all vacuum hoses for cracks or disconnections.
• Use a vacuum gauge to measure engine vacuum; low readings may indicate a leak.
• Replace any damaged hoses or gaskets as needed.

3. Clean or Replace the MAF Sensor

• Tools Required: MAF sensor cleaner or electrical cleaner, socket set.
• Carefully disconnect the MAF sensor connector.
• Remove the MAF sensor from the intake.
• Spray the MAF sensor with cleaner and let it dry completely before reinstalling.
• If the sensor is faulty, replace it with a new one.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge, safety glasses.
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition to the "ON" position (do not start the engine).
• Record the fuel pressure; it should be within the manufacturer's specifications.
• If pressure is low, inspect the fuel pump and filter for issues, replacing them if necessary.

5. Inspect Fuel Injectors

• Tools Required: Socket set, fuel injector cleaning kit (if needed).
• Remove the fuel rail according to the vehicle’s service manual.
• Inspect the fuel injectors for clogs or leaks.
• If necessary, clean the injectors with a cleaning kit or replace them.

6. Check Engine Coolant Temperature Sensor

• Tools Required: Multimeter, socket set.
• Locate the sensor and disconnect the electrical connector.
• Use a multimeter to check the resistance of the sensor against the specifications in the service manual.
• Replace the sensor if it is out of specifications.