Stock y-pipe???
 

Hey I've been researching for like three hours trying to find my stock y-pipe size on my 2000 trans am, I have gotten everything from it being 2 1/4 to 3" lol. Reason being is that I looked under my car the other day and I have an enormous hole in the muffler, so I patched the hole but I bought the flowmaster setup a guy had here in the classifieds, however that's a 3" pipe so IDK if that'll fit or not, and if it's close enough idk if I could just expand my y-pipe to make it work for me. (Yeah I know when I patched the muffler I should've just measured the diameter of the y-pipe while I was down there. :knock: )

Anyone know for sure off the top of their head?? Am I just googling the wrong thing??? Lol

The stock I-pipe that connects to the y-pipe is 2-3/4". Most catbacks actually have a stepdown from 3" to the 2-3/4 to connect to the stock y-pipe. I think each side of the y-pipe is 2-1/4" but the driver's side is flattened as you can probably tell. I think Borla makes a 2-1/2" round stock y-pipe replacement. I had one on my 2000 SS until I upgraded to headers.

i have a high flow SLP y pipe. not flat. for sale too.
i could measure it tomorrow.

That's the one I was thinking of, I mixed up Borla with the SLP.