I was driving my max on the highway. I pulled away from a stop sign and at ~40mph I downshifted to 2nd gear and punched it to the floor. Suddenly the exhaust popped and now it is SIGNIFICANTLY louder than it was before, sounds awful. It sounds like a V8 pick-up truck from the early '90s haha.

Info on the exhaust -------
Stock manifolds, Warpspeed Y with new (less than a year old) gaskets to manifold, test pipe welded in, the rest is all stock.

 

Look for holes when its cold. If the pipe isn't broken, clean it somewhat, put on furnace cement $11.89 half gallon at home depot, let it sit for a hour then drive until warm. This product withstands heat up to 2000 degrees, six times more than jbweld.

 

This happened to me, similar setup (Y, high-flo cat, stock cat-back). For me it was the muffler/mid-pipe connection. First got a replacement muffler/kept stock mid-pipe (stupid, it was all rusted too) then not long ago gutted the whole thing and did a full cat-back.

I know you have rust in your part of the country. My money is on the stock parts.

I had a two-in-one laser pointer/blacklight laying around, used it at night to clearly see where the smoke came from, no need to jack up the car. You can probably do something similar and I advise to just finish off the exhaust and throw away the crap stock parts.

 

Yeah! I was like "sweet +50 horsepower".

Mine rusted out along the curves of the stock muffler. Good excuse for a new exhaust

 

I had the same situation happen to me at the track. Shifted into 2nd (stage3 clutch aint no joke) puaaaaaaaa my exhaust got loud as he** lol my muffler had broke off from one of the welds.

 

I had that happen when right after I had put my WS Y & magnaflow cat into a crappy crush bent Mieneke cat back. Blew the tip out of the muffler box (rust helped). Helped me get into the stainless Stillen cat back I have now.

 

Furnace cement is *******. I used that to seal my Y-pipe for good after the cheap Felpro gaskets failed 3 times.

 

Alright guys, awesome.
If my ears aren't fooling me, it sounds like it's coming from the front end of the car.
My guess would be on the gasket from the manifold to the Y pipe as that's where the sound seems to be coming from, although it could be anywhere in that area.

I would be much happier if it were further downstream as I would gladly use this as an excuse to replace the whole thing

 

Take it to a muffler shop and have it rewelded......