Question

What sensor is the engine code P0171 system too lean bank 1 on my 2007 GMC Yukon? Traction and engine light

Answer 1

Hi there,

This code can be caused by a few different issues, check and make sure you don't have any leaks on the intake manifold. The sensor that could be the culprit would be the front O2 sensor on bank 1. If it's reading wrong it can cause a lean fuel mixture.

Answer 2

P0171 GMC Code - Fuel Trim System Lean Bank 1
Read more: https://www.autocodes.com/p0171_gmc.html