They are the same things, average joe is correct on what they mean.

The LS4 has AFM/DoD that shuts down 4 cylinders at cruising speeds, being a early design still they are pretty prone to burning oil and having a possible DoD lifter failure. If that was either shut off or removed completetly the engine will burn far less oil or even none if it never did in the first place. If it was completely removed and was like a standard 5.3 LS it would be rock solid.