Okay my turn to jump in with .02 worth.. Wifes tahoe was throwing a bank rich code.. hmm.. rich..okay I can live with/pittle with fixing this.. ended up replacing the fuel pump..internal.. pump feeds internal filter.. hose between the two had blown a hole in the side.. (anurism) .. got that fixed and no codes...

NOW since it was saying rich.. and obviously with a hole it was actually starving... 02 sensor reading gases?.. says lean and crank open the injector cycle.. and computer says hey we're running rich on this cycle..lets warn somebody?
Just love the computer age!