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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect for Vacuum Leaks

• Tools Required: Vacuum gauge, spray bottle with soapy water.
• Inspect all vacuum hoses and intake manifold gaskets visually.
• Use a vacuum gauge to check for proper vacuum levels.
• Spray soapy water around suspected areas; bubbles indicate a leak.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner (if cleaning), screwdriver set.
• Remove the MAF sensor from the intake.
• If cleaning, spray the MAF sensor with the cleaner and allow it to dry completely.
• If replacing, install the new MAF sensor following the manufacturer’s specifications.

4. Check and Adjust Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine to check the pressure.
• If the pressure is below specifications, inspect the fuel pump and fuel filter for issues.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaner (if cleaning), multimeter (for testing).
• Remove fuel injectors from the rail and inspect for clogs or leaks.
• If cleaning, use an injector cleaning kit according to the manufacturer's instructions.
• Test each injector's resistance with a multimeter; replace if out of specifications.

6. Replace ECT Sensor (if necessary)

• Tools Required: Socket set, torque wrench.
• Locate the ECT sensor on the engine.
• Disconnect the wiring harness and remove the sensor.
• Install the new ECT sensor, ensuring it is torqued to manufacturer specifications.
• Reconnect the wiring harness.