do fuel system cleaners really work and if so, whats the best one

Hello, everyone has an opinion, but I can't think of a single practical use of a "fuel system cleaner" that can affect an actual symptom you're having. Do they work? On a nominal level, yes, but for a non-direct injected fuel system like in your 2012 GMC 1500, the fuel detergents in gasoline as standard do all the cleaning that is needed, and additional additives are generally not productive. www.repairpal.com/repair-shops