I don't know why there's so much negative talk in previous threads about the TSP y-pipes. I bought one hoping I could have an exhaust shop make it work with some eBay headers I bought. I heard the TSP y-pipe was in the most pieces so I figured it would make a good starting point and the exhaust shop could modify it as needed to fit. After I installed the headers I decided to see if the y-pipe was even close to lining up. So I laid it out on the floor and lightly clamped the sections together with the clamps that came with it so I could handle the whole y-pipe at once. Used the floor jack to hold the back of the y-pipe while I tried to fit the front to the collectors. It literally slid into place and tucked up so nicely that I couldn't believe it. It tucked up way better than the factory y-pipe but it was probably sagging due to the completely worn out motor mounts. I used a floor jack and a bottle jack to press the y-pipe up to the floorboard, welded everything up, lowered the jacks to relieve the pressure and the y-pipe settled a fraction of an inch to fit perfectly. The merge collector on the y-pipe lined up perfectly with the I-pipe or whatever it's called that runs to the muffler. Cut about 2 inches off of the I-pipe... did the same thing... jacked it up a little higher than it needed to be, slipped them together, welded it and released the pressure on the jack. It's been problem free for a couple of months now. No leaking, no banging the floorboard, has more ground clearance than the old y-pipe, it's built very well for a fair price, and on and on... I couldn't be happier. And the sound with the cutout open

It sounds like a cup car. I thought for sure it was going to sound like crap with nothing to muffle the exhaust but somehow it sounds clean and crisp. Even with the cutout closed so the exhaust goes thru the factory muffler the tone is considerably more aggressive without the cats. Just my experience with my TSP y-pipe FWIW.
P.S. The eBay long tubes that aren't supposed to fit worth a damn also fit like a dream.

I'm not saying every set produced is perfect but mine seem to fit just like they should.