Does a cat-back replace the stock cat? or does it bolt on to the flange after the cat?

the reason I ask is because the shop I had do my first exhaust cut off my exhaust flange after the cat.

I'm looking into the GMPP Performance cat-back now.

 

Would you mean noob?

And no, a cat back replaces just that, from the cat on back. So right after your cat theres a flange where your "cat back" bolts up

 

n00b, nub, newbie...all the same lol.

See heres what I mean...no flange:


How hard would it be to put a new flange on?

 

when i wanted to put my stock muffler back on with some cheep piping my shop said they didnt have that type of flange and couldnt get one...

 

hmmm...well, I do know some kick ass welders...
I could reasonably chop off the flange on the cat-back and weld that on the piping?, correct?

 

well you need 2 flanges to bolt a catback but yes you could do that.

 

The other type you're thinking of is "header-back" which attaches after the downpipes.