A bit more info...
The cats are used, sold to me by Gundo. Someone above posted that it could be failing cats, but I doubt very much they are. I inspected them in and out before install and there was nothing loose or moving around inside. Beyond that, I have no idea how I'd know if they were bad. Checks via Durametrics diags shows nothing and no cels in 50 miles.
After a proper warm up, say 15 minutes, the annoying nasal/tonal quality is reduced. Not GONE, but less irksome.
Windows down, frankly, the car sounds like most cheap imports I've heard over the years with ridiculous fart cans as I pass 2,600rpm and through 3K. Below that, it's fine. But in that range, something isn't resonating in a happy fashion. By rasp, this is what I mean. If you've ever watch Conan O'Brien when he does his nerdy-guy impression...this is the first thing that pops to mind when describing it. haha...
Windows up, not nearly as bad, but not melodious.
I'm on the fence between just going back to stock or replacing the headers and cans. Maybe headers and the gundo hack? Volume isn't an issue with me as I come from rather loud American iron for the most part, but tone is SUPER important to me. I also have an '07 Boxster S with the Remus race system and the sound is just pure sex. No way in hell am I shelling out the cheddar for the 997 Remus system however, so I'm going to have to do the best I can with the budget I've set for the car.
I'm sorta bummed...so many people have posted being absolutely thrilled with how their cars sound after replacing just the cat pipes. But I can't see for the life of me how anyone would find this tone pleasing in the slightest.
