well i just found out that a 94 vetts cats are bolt in so im going to bust that guts out and get some free hp out of my vette. anyone have a how to on this subject. also if i get an inspection done that doesnt require an emissions test will they fail me because it sounds like the cats are hollow. what is the fine for hollowing your cats. if you throw codes after doing it where do you get the o2 sensors that trick the computer. are they hard to put in.

 

ooooh... all that free power... 10hp... wow... you are gonna be so fast... and at what expense? POLLUTING OUR AIR.



There are aftermarket highflow cats that will work just fine... and the loud that will come from no cats could easily make your car way too unbearable.

The fine? If the EPA wants to, it could be as much as $10k. Keep that in mind.

The O2s are before the cats and don't care.

 

did you know that cigaret smoke pollutes the air more than car exhaust. read that somewhere. well i guess ill wait for a few more opinions before i decide. how long would it take to get them off. im thinking that im going to bust them out in the middle of my apartment parking lot so you know i want to be in and out real quik lol

 

oh one other thing. my left cat is making a rattling noise at idol. is it likly that i could take it out and shake out the loose piece and stick it back on. i realy dont want to pay 300 bucks for a new stock one.

 

i just noticed that you are from ca. so i can see where you would get affended about poluting the air since you have to where a gas mask why sitting in traffic in la. well we got plenty of room for polution on my side of the country.

 

I think Bogus' point is that don't expect a big gain from hollowing out your cats. Although since it sounds like your cats are clogged, maybe you'll restore some power. anyway-

The cat on my '85 (I only have one cat), was making a terrible knocking/rattling noise. I took it off and the pieces just fell right out. I also passed emissions with the hollow cat... which I thought was sad and funny.

Maybe you want to check out some high flow cats, they are cheaper and work better (less restrictive) then the OEM ones.

 

I did it out of necessity years ago on a Ford truck-if there clogged now, and it sounds like one of yours is shot you'll probably notice quite
an increase in performance and even a possible increase in mileage.
Of course I agree with Bogus-but, an internal combustion engine will
polute less if it's tuned properly and the internals are in good shape
(rings etc) rather than clogged up and running poorly.

 

don't confuse me with living in CA as agreeing with CA.

However, being responsable is another thing.

Think about it... About 15 of the 50 states are not mandating cats remain on the car. Period.

Now, gutting cats is a nasty idea, if only cause of the loss of performance. But also due to the increase in emissions.

If a perfectly tuned engine would pass smog tests at all engine speeds and loads, do you really thing the auto makers would continue to use them? I doubt it.

The answer here is this: As it stands, the EPA makes emissions testing a state by state issue. One that can be addressed if needed and mandated by the EPA. However, there is no guarentee that these rules won't change overnight and all states are required to do some form of testing. These tests may not be as stringent as CAs tests, but they could be a lot more difficult than you are ready to deal with.

I guess you are young, and don't remember those glorious days of the 1970s... yee-ha. As a kid, I remember piles of snow turning brown, then black, within 2 days of a storm ending. It was most gross. And the cause? Particuate emissions.

Pittsburgh, PA's air was so bad in the 60s that headlites needed to be used at noon.

Bastet44's mom grew up in LA, near USC's Campus. She remembers the air being so caustic that is would make her lungs hurt.

My question to you: How can you (and others who so blatently disregard these laws) remove these emissions controls, just so your car sounds "better" (it don't) and goes "faster" (it won't)? It's pure selfishness to me.

I don't know how anyone can say, with a straight face, that elims (straight pipes) are quieter and less boomy than Corsa's. I ran elims and they damned near killed me - and I think left me tone deaf because of them. The Corsa's are the quietest things on earth...

Cats also have the ability to smooth out the exhaust gases as they come out, which will help exhaust flow. Just cause the numbers are lower (CFM) it does not mean there isn't a scale of efficency going on.

Also, if these cats were SO piggy, why are many LT1 owners getting 260~275hp at the rear wheels? The math supports that these cats are not robbing the engine of much power (using 15% manual, 20% automatic power losses).

The same applies to the LT4, those things are getting 295~310hp at the rear wheels...

I wish people would realize that modern engines are part of a well engineered and integrated system, and no longer the victims of a tacked on and pieced together process. Sure, that applies to the L98 systems, but even they matured, however, the LT1 systems are much more integrated and reliable.

The LSx? Damn... nearing perfection....

 

I hope your state doesn't have emission testing, cause you'll never pass.

 

I belive you would be better off going for two, 3 stage, high flow cats.

Besides, you are on my side of the country and I would still like cleaner air.

My $0.02

 

to the original poster......although i have an l98 w/factory configuration (not factory parts): lt headers/cat-less front Y >>> hi flow main cat >>> rear Y/cat-back w/open mufflers......
i can tell you its still PLENTY loud.

granted, i do have cam, etc.
but i ended up replacing my gutted/test piped main cat with another new hi-flow one because the sound before was SO LOUD that i routinely set off alarms on nearby parked cars (hell, i still do sometimes). this might seem "cool" and "really neat" to some of the younger folk, but you'll grow out of it quickly enough.

do i love the sound, even with 1 cat? yup. its all more than plenty as i mentioned. i can foresee the day when i'll probably end up with another cat-back that'll supress the sound a bit more, as i get a little older. hell, i've already blown out my ears from years and years of Led Zeppelin jammed to the max everywhere i went

just take it from me, don't blow your ears out just to show off to your pals. as others have stated, get yourself a new pair of aftermarket hi-flow (bullet?) cats designed for your lt1 and call it a day. you'll no doubt be happy you did

 

I Have Stock Mufflers And There Realy Quiet. Are The Cats Going To Make It Alot Louder Even Though It Runs Realy Quiet Now