I've heard a borla exhaust cat back system on a 6 cylinder 3.5 tacoma. Imo, you can send it back to them. They sound good if a V8, but not a six . V6 engines just sound like chit with any aftermarket muffler. They sound bad enough stock already, no need to make it worse. The toyota trd muffler had a far nicer sounding system compared to it.