Cat troubles...just lose it??

[deftdrummer]

My question is this: besides the fact that it's not legal to drive around without a cat because its loud and emissions go through the roof, will it start smoking dark black smoke from out under the car too?? I heard from someone driving without a cat or exhaust (for that matter) will do this. Is this true??

p.s. one more thing, will any sensors be tripped that would make the check engine light come up with a code?? Im thinking yes.

[Z3Px]

i very much doubt that it will, i have a friend who replaced his cat with a 3" test pipe, and it runs fine. now it probably wont if you take out the cat and the exhaust mind you

[Nismo_Freak]

The black smoke is excess fuel being passed through the exhaust.

Your car will not do this unless it runs really rich.

[deftdrummer]

i very much doubt that it will, i have a friend who replaced his cat with a 3" test pipe, and it runs fine. now it probably wont if you take out the cat and the exhaust mind you

well, your friend probably still had a muffler on his car so the exhaust passed through there. But anyways, im still going to have my exhaust "hooked up" if you will. there will just be a gap between the mid pipe and exhaust where the cat would be so technically there would be no exhaust passing through the muffler. I also heard that the noise gets progressively louder over time?? im not planning on having no cat by the way...just until i buy another stock one.

[Nismo_Freak]

Ooo.. thats gonna be really loud.

Just gut the cat... hook it up, and fix it when you get the chance.

[deftdrummer]

thats a good idea freak, cause im thinking that something broke inside the cat causing the rattle. Isn't there glass and $hit in there that could get broken? so gutting it would basically be holding it upside down over the trash :-)

[captain nismo]

Ooo.. thats gonna be really loud.

Just gut the cat... hook it up, and fix it when you get the chance.

Yeah its quite loud. I have an exhaust leak near the cat and its very loud inside the car. The sound is very "harleyish"

[PapaSmurf2k3]

im pretty sure you can drive around without a cat "legally" if it passes emissions without it. (at least in some states), also, as long as you have the muffler, the exhaust wont get much louder from removing just the cat. I have an exhaust leak at the flange just before my cat, so im just about done with catalytic converters (im on my 3rd one since i owned the car). as long as it isnt too big of a leak, it wont really sound like a harley as much as it will sound like a tapping. (at least mine sounds like tapping, it might be different for a leak post-cat)

[deftdrummer]

well the thing is, im not even going to remove the muffler (cat back HKs dragger) im just going to let it hang there until i get paid so i can buy another cat. If its too horrible then ill just clean out the cat and put it back on there

[Nismo_Freak]

im pretty sure you can drive around without a cat "legally" if it passes emissions without it. (at least in some states), also, as long as you have the muffler, the exhaust wont get much louder from removing just the cat. I have an exhaust leak at the flange just before my cat, so im just about done with catalytic converters (im on my 3rd one since i owned the car). as long as it isnt too big of a leak, it wont really sound like a harley as much as it will sound like a tapping. (at least mine sounds like tapping, it might be different for a leak post-cat)

Incorrect... you must have a working catalytic converter on your car if it's above an 84 model year, IIRC on the year.

It will be really loud, enough to attract attention from the police.

Just gut the cat... so if a cop looks under your car for any reason he will see it.

[PapaSmurf2k3]

what will be really loud? if you unbolt the cat from the rest of the exhaust and let it hang there (yeah thatll be freggin loud, baisically what my car is, catalytic converter to pipe that dumps out the side, no muffler), or run no cat, because ive known people that run no catalytic converter at all and it sounds normal with stock exhaust.

[deftdrummer]

well i want to theoretically run no cat and no exhaust. I started my car up with nothing after the cat when i got my exhaust and that sounded damn good i though! Is it worth it? Im definetely taking it off though. I want to see what it sounds like and what kind of crap is clanking around in the cat itself. If there's nothing in there i want to see if my car still makes the rattle noise. If it does...it's not the cat!

[deftdrummer]

**UPDATE**

I took the cat off (after some hassle, bolts snapping, exhaust hanging) and man this thing is LOUD AS ALL HELL. I knew it would be loud but not this loud! So i just ordered my hi-flow cat from heavy throttle, i think i just had a leak at the cat because the gaskets were crap. By the way...the second cat isn't even a cat! its just hollow, and ive heard about this before but i thought in california 240's always had 2 cats??

[crzycav86]

Ooo.. thats gonna be really loud.

Just gut the cat... hook it up, and fix it when you get the chance.

I always heard that gutting the cat does more harm to performance than good. That's because of the turbulence that the air has to go through when it passes from a smaller pipe into a big hollow canister and then back into a small pipe... at least thats what goes on with the cavaliers.

[deftdrummer]

mine isn't gutted...its just nonexistant!

[Nismo_Freak]

I always heard that gutting the cat does more harm to performance than good. That's because of the turbulence that the air has to go through when it passes from a smaller pipe into a big hollow canister and then back into a small pipe... at least thats what goes on with the cavaliers.

Somewhat true but not really.

Imagine breathing through a cheesecloth that's about 5" thick.

[NISTECH]

ummm i would look in the muffler for the interior contents of that cat in the picture. shake your muffler and see if it sounds like a miraca.

[Nismo_Freak]

ummm i would look in the muffler for the interior contents of that cat in the picture. shake your muffler and see if it sounds like a miraca.

S14s have two "cats" ... the first one is in the manifold itself and is found on all S14s. The secondary one is a cat on some vehicles but not on all of them, the majority have an empty one (mine was empty).

[deftdrummer]

indeed