Question

1999 GMC Sierra SLE 5.3L with DTC P0174, what is the fix?

Answer 1

P0174 Fuel trim lean Bank 2

Vacuum leak are the most common cause for a lean fuel trim . when you get this code your getting more air than fuel on one side of the engine, vacuum leaks can come from disconnected vacuum hose to leaking intake manifold gasket, before any fix do a inspection.

Answer 2

P0174 GMC Code - Fuel Trim System Lean Bank 2
Read more: https://www.autocodes.com/p0174_gmc.html