Is it possible to have headers, a high flow cat, 3" cat back exhaust and not have it too loud? I wouldn't mind the car being a loud when I open it up but I don't want it to be annoying during normal driving, or have something that attracts cops like crazy.

 

Sure its possible. It all depends on the muffler.

 

Longtubes through a cat will be quieter then manifolds through a cat. My longtubes through a cat and hooker exhaust was as quiet as stock at idle.

 

I agree that it's the muffler has the most effect on the loudness of the system. A free flowing cat will also increase the sound level. I started with a flowmaster muffler; later when I added headers and a 3" intermediate pipe, the exhaust didn't get any louder. Later when my cat clogged up, After I "unclogged it" the exhaust note was much louder.

 

My buddy's 93 Z28 with Hooker long tubes and 3" Hooker Aerochamber cat-back exhaust is still quieter than my stock manifolds, gutted cat thru stock cat-back into Flowmaster setup. Mine idles louder and pretty much drowns out the Hooker at WOT. The Hooker has a very nice throaty sound with the headers though. Not loud at all at idle or part throttle driving.

 

If you want quiet use a Borla with the full block off plate. It will be quiet as stock.