Cccaaatttsss
 

Has anyone taken off their catalytic converter yet? any power change?does it add torque with hp or just hp?

naturally you will have a HP gain since your freeing up the exhaust.

but i wanna know what exactly will happen to my car

you will prob get a lil gain and you wont pass inspection without them...

Don't do it. Its not worth it. Either buy high flow cats or if you're extra crazy go for resonated test pipes. Replacing your cats does a few things.

1. Won't pass smog.
2. Illegal.
3. Sounds TERRIBLE
4. Makes your car smell like a gas station
5. Makes you wish you listened to me when I typed the 4 reasons above.

I have test pipes which(if you don't know) is a pipe which replaces the CAT with a straight pipe. Honestly it didn't add hp, it just shifted my torque and HP curves higher on the powerband. Which is nice, but is also loud and raspy. Sounds terrible.

If it wasn't such a PITA I would put my stock cats back on. But for now its too hot outside. When I get a cool weekend day I'll switch back to stock.

No, I don't think anyone in the whole VQ community has ever taken off their stock cats. Who's going to be the first? :icon17:

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The same doesn't apply to all.

My resonated test pipes made my exhaust sound alot better. But at the same time, it did make it a whole lot louder & added more drone. Not so much rasp though at WOT. And no rasp in DD.

As far as power, test pipes will always yield better power than HFC. Better yet, with a tune, the extra flow of test pipes really show a good increase in mid & high-end power.

Test pipes isn't for everyone, thats for sure. I would never recommend any non-resonated test pipes. But even with the resonator, it still alot less daily driveable than HFC; the smell, loudness, and risk of getting caught are alot higher with any test pipes.

As far as rasp, it all depends on the exhaust you are going to pair it with. Some will rasp a whole lot, some will have very little rasp.

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No officer... I haven’t touched my catalectic converters:2:

I say give it a shot. I don't think it sounds that bad. Plus I could tell a difference with my intake, plenum, headers, and exhaust. From mid it feels strong. Car sounds very loud but I actually like that so its really what you want. I live in maryland and have texas plates so cops don't bother me too much. They get behind me and then after a minute, leave.

I heard taking off the cats will make it sound louder so the guy was gnna put in a glass pack and it will unlock alot of stored away power. It wont pass smog but he also does illegal smog for 150 and he can make me customized header which woulnt pass smog anyway.So i dont know if i want t do it yet but if i get it done im getting a bunch of illegal s***,cuse it would be a waste of time not to.

Just knock the insides out of the stock cat. Then you can't see a difference. I know we all have our reasons for doing what we do, which is all fine and dandy... but don't get too cocky there buddy. I've seen some guys in "tuner" cars being pulled over, and while they're at it, the cop takes a mirror and looks for your cats...

Again, your odds of this... slim (unless Cali). But in the very back of your mind know that it's $25,000 fine and some jail if caught (I think- God, I sound like Q45Tech...). Tons of people here have it done. Just do what ya want. Def get resonated pipes...

High flow cats are a good replacement if you want to add a little power and add volume to your exhaust. Without turbo(s) to help quiet down the exhaust you will get a decent amount of rasp without cats which sounds like crap on a luxury car.

ok then maybe i wont get them. but i read on alot of sites thats theres no such thing as high flow or perforance cats

Do not punch your cats like the other guy said.. You will lose power and have major exhaust leakes.

Test pipes have big potential for power and not all test pipes sound bad.

Crawford HFC here... and very worthwhile (after re-tune)... the they post that said another forum said there is no such thing as high flow cats (or they don’t work or whatever they said), I'd suggest staying out of that bs place... you've found a good source here (G35Driver).