A boost fooler fools the computer into thinking the turbo is not exceeding the manufacturers (DC) limit. Without the boost fooler, every time you exceed the limit, the computer will defuel the engine to cut back.
The boost elbow actually closes off a portion of the boost signal going to the wastegate actuator. It makes the actuator open at a higher pressure. By doing this you can run higher boost numbers for cooler EGTS
Did you buy your truck with the add ons already there?