my GMC Sierra T1XX (2019-Present) has a P0171 code, what does this mean?

Learn how to diagnose and fix P0171 lean fuel condition in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

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

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visual inspection of all vacuum hoses from the intake manifold to the throttle body.
  • Use a smoke machine or carburetor cleaner to identify leaks.
  • Replace any damaged or cracked hoses.
• Tools Required: Smoke machine, carburetor cleaner, screwdriver set.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor along the air intake duct.
  • Disconnect the electrical connector.
  • Remove the MAF sensor using a Torx screwdriver.
  • Clean the MAF sensor with MAF cleaner and allow it to dry. If damaged, replace it with a new one.
• Tools Required: Torx screwdriver, MAF cleaner.

4. Check Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail service port.
  • Turn the ignition to the "ON" position (do not start the engine) to check pressure.
  • Compare the reading with manufacturer specs; if low, investigate fuel pump or filter issues.
• Tools Required: Fuel pressure gauge.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the intake manifold or relevant components to access fuel injectors.
  • Check for proper operation and any signs of clogging.
  • Use a fuel injector cleaning kit if necessary, or replace injectors if faulty.
• Tools Required: Fuel injector cleaning kit, socket set.