Differing opinions on that. Maybe 5hp by itself. 10 if you match a good muffler to it? There are those that claim 10hp with a cat delete, but I think that may only hold true with MAJOR mods. You can get close with the right performance cat, so for that reason, it'* worth keeping.

I don't want to get caught without one, and I'd like my exhaust to be worked on by a pro, which wouldn't be possible if I had deleted the cat.

That makes sense.but I have TOG Headers, Borla Cat back Exhaust...and Stock CAT.....HighFlow CAt iin this setup..maybe 5-10hp eh?

If your cat is clogged it may gain you BACK that lost hp, but it probably wont increase your hp especially with togs and ct-back.

I'll go with that. The routing and components in the 2000+ SSEi'* just LOOKS less restrictive. I know alot of guys are running in the 13'* with stock exhaust.

I think GM paid alot more attention to the exhaust post-99.

The difference between a stock cat and a performance unit is less than 10% when measuring CFM'*.

If I remember right all the bonnies in the 13'* currently have stock exhausts (at least from the cat back). I could be wrong though...

Hey, my redneck exhaust guy suggested putting some adapters and a 3" cat in. Good idea?

L27? Completely unnecessary. Hi-flow 2.5", and you won't be able to outflow it.

I can't figure out how you meant that yet.... So I'll just take it as advice with no underlying L27 hating going on... Thanks

Simply put, if an L67 can't outflow one, you'll be ok with the 2.5", as long as it'* a performance unit

The extra price of a 3" with adapters probably wouldn't be worth it for the returns in performance.

This is exactly what my Cherry Bomb glasspack looks like inside..."perforated"...and the reason I chose it to preceed my MagnaFlow stainless muffler. Cool.
Now that I know what the MagnaFlow looks like, if I need to replace the Cherry Bomb, I've got a confirmed visual that it is virtually identical, except the body is stainless steel. Excellent. :P
Thanks, Will.