Okay first of all, running with no cat is just irresponsible. You're dumping raw exhaust fumes into the atmosphere and that's just no good.

If you are absolutely convinced that on an internally stock LS motor that the stock cat is holding you back, at least replace it with a high flow cat.

I'm not going to argue that the high flow cat doesn't have more flow capacity than the stocker. That said, an LS motor isn't going to push out enough exhaust gas such that the flow capacity of the stocker is exceeded.

 

High-flow cat is the way to go. My carsound cat, installed for 2 years, just took a dump on me though. The internals are rattling in low rpms and when i'm in VTEC my car gets 10x louder than before Just what i need....

 

this is true, it does release nasty exhaust gasses,
try telling that to v8 muscle cars
besides that, i'm just letting the guy know that you can free up a couple hp, from removing the cat, and yes you feel a difference, i have been in the game for a long time, i've been there and done that,i'm not a ricer wanna be, but if you live in a state that makes you have a cat then , yes a high flow cat will work, then again if you build your motor to much, you will have smog problems anyway, owner makes his own choice, just my 2 cents

 

There are plenty of V8 muscle cars (at least newer ones) that run cats too.

You should run a cat not because the state you live in makes you, but because you don't want to run around polluting the air.

A highly built motor is still fully capable of passing smog with a good cat and proper tuning.

 

if your worried about the air, then by a civic hybrid, or something else along the line, better yet don't drive at all,
i'm done with this thread
peace

 

Why say that?

You can still have a perfectly eco-friendly car that makes plenty of horsepower. There's no point in screwing up the environment just because a test pipe is cheaper than a cat.

 

Im sorry, regardless of the argument, anyone who says "ive been in the game a long time, been there done that" is just plain lame.