Racing 'test' pipe for catalytic converter

[legendarysnail]

I'm pretty sure the cat is f'ed on my S13 (hesitation bad, rotten-egg smell) and I don't have the money for a new, high-flow unit.

So after long, excruciating minutes of searching for an alternative, I found the website www.racingpipes.com, where they are selling a racing test pipe that replaces the cat on 240's. My question is this: will removing the catalytic converter and replacing with a straight pipe, on a virtually stock S13 (KA24DE), screw with the computer?

This exhuast shop I went to said it would, but the guy who said that isn't 240-literate and didn't even look at the stock cat.

Thanks for your time,
Evan

Oh BTW, I come from Fresh Alloy...bastards always have to add something negative and ruin every discussion. Hope y'all are more mature here :bow:

[timmybgood]

a test pipe won't mess with the computer. if you're really feeling cheap though, just use various prodding objects and hollow out the cat. when i put my exhaust on i discovered that my cat was completely hollow for sheer use!

[legendarysnail]

Hmm...that's an idea! Thanks...

[AlligatorBling]

ive had a testpipe on my s13 for a few months now, ive seen no problems yet.

[legendarysnail]

Do you know how hard it is to gut the stock cat? I mean, is there anything in there that would require ungodly force to push out or something? I'm thinking about doing this tomorrow, then on Friday (payday) getting this muffler I have, installed.

[encasemyheart]

It's easy. Just use some pipe or something to push it out. It is hard material though. What I did was use a pipe and hammer to break the layers of inner material and then it just falls out of the bottom. Granted, it is not a good idea because of all the turbulence it creates in the exhaust.

Also the stuff inside it is a carcinogen, maning it causes cancer. So dispose of it properly and don't inhale the dust.

[legendarysnail]

I realize it'll create turbulence than wasn't there before, but it's gotta be better than stock, eh?

[PARAD0X]

get a drill and a really really long bit. and hollow it out as much as you can

[encasemyheart]

Originally posted by legendarysnail
I realize it'll create turbulence than wasn't there before, but it's gotta be better than stock, eh?

It usually depends on who you talk to. Some say it will give a power increase despite turbulence, others say the turbulence negates and extra flow you gain.

Either way the gain is minimal.

On my old turbo Eclipse (97 GSX) I gutted the cat while I had an upgraded turbo and cat-back, I believe I was running 16psi or so, even then after gutting the cat I didn't notice a power difference. No smell either like some say there will be. The only thing was the sound, it added this raspy noise that really sucked. I personally wouldn't gut my cat ever again.

[twitchy]

i had the cat removed from my 93

effect:
-tinny, raspy sound with stock muffler
-car noticeably used more fuel
-you could smell unburnt fuel out the tailpipe
-engine light never came on

when I reinstalled it later (I couldnt take the sound) there was no change in the power, nothing noticeable

cutting it off is useless for power, and not having one will not hurt, albeit your mileage and ears!

[240 2NR]

Since most people say that gutting the cat is useless, I'd say avoid doing it.

You'd probably be best off just unbolting the exhaust and having a look at your cat to see if it's clear or of it really is F'd up rather than assuming. If it is and it's not functioning then gutting the cat would be the cheap and easy solution and would improve current performance, though possibly not the best for ulitimate performance or the environment.

If you are still considering a test pipe, I would just wait an extra week or two and shell out the bucks for a high flow unit. The gains are roughly the same while keeping you legal. A non catylized cars is pretty easy to smell if you drive behind it and the fines if caught (minimal risk, but still present) can be huge. For how transparent cats are in modern cars, and for how well they work, I see no reason to remove one or not equip it, save for a dedicated track whore.

It won't effect your engine computer, all emmissions equipment is located in front of the cat.