Catted SZ's 3 to 2.5 testpipes and resonated 2.5 B&B catback. It's super quiet most of the time and minimal highway drone.... Love it.
It was a huge drone cutter adding the catted test pipes vs the normal resonated test pipes... quieter at idle too and low RPM. Only downside is I lose about 10hp or so... who cares.. not me.