I'm running a header, flowmaster and all 2" pipe. w/o a cat I think its a little loud, but it doesn't sound bad. I've had stock manifold and cat to 2.25" pipe w/turbo muffler and it was actually pretty quiet. Also had a 20R w/header 2.5 and glasspack once for maybe 2 weeks after buying the truck - obnoxious to say the least.

Helped a friend install a borla cat-back on a v6 pathfinder a few months ago, it sounds NICE. It was smooth and throaty, but lacked the trumpet/crackle my flowmaster makes at 3k rpms. He by-passed the cat to see what it was like and it still had a NICE tone, but not too loud.

Go to main menu, offroad video, Justin in the dirt here and you can hear the borla system in action!