how to fix P0171 lean code in Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

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

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect all air intake hoses and connections for cracks or loose fittings.
  • Replace any damaged hoses.
  • Check the intake manifold gasket for leaks and replace if necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake.
  • Clean the MAF sensor with MAF cleaner spray if it is dirty; let it dry completely before reinstalling.
  • If cleaning doesn’t resolve the issue, replace the MAF sensor with a new one.

4. Test and Repair Fuel System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position (without starting the engine) and check fuel pressure. It should match manufacturer specifications.
  • If the pressure is below specifications, check the fuel pump, fuel filter, and fuel lines for clogs or failures. Replace as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the fuel rail and inspect each injector for clogs or leaks.
  • Clean the injectors using an ultrasonic cleaner or replace them if they are clogged or damaged.

6. Reassemble and Test

• Reinstall all components in reverse order of removal.
• Reconnect the battery.
• Start the engine and check for any leaks or abnormal sounds.