nighthawk350z

may seem dumb but the only way to find out is to ask... are high-flow cats street legal?

ChrisMCagle

Technically...no.

They are "for off-road use only".
Sooooooo... make sure to use them "off-road". Hehehehe!!

orhanz33

really? so test pipes and high flow cats are both illegal for streetuse? wouldn't it depend on the cat?

Gsedan35

iTrader: (10)

http://www.epa.gov/otaq/cert/factshts/catcvrts.pdf

Here is the letter of the law on when you can replace a oem converter and for what reason. Test pipes are 100% illegal according to the feds. (I'm just telling the law, not saying anything else, I don't have a position on do or don't).

"If the vehicle is more than 5 years old or has more than 50,000 miles. (8 years/80,000 miles on 1995 and never vehicles). and a legitimate need for replacement has been established and appropriately documented (e.g., a plugged converter or unrepairable exhaust leaks).

Aftermarket converters subject to the enforcement policy requirements cannot be used for replacement if:

(1) the existing converter is present and functioning properly.

The penalties for violation of the above are up to $2,500 per person.

ChrisMCagle

Thanks! Good info. I've been looking all over the web for the specific laws.

Actually, there is one correction I need to make to your post. It's a $25,000 fine, not $2,500. (I don't like that one bit!)

-Chris

ares

iTrader: (2)

just dont take it to emmisions with them, I dont think cops are carrying a portable emmisions tester yet.

but I must say, I thought they kept you emmissions legal, whats the benefit to paying so much if your in the same boat?

ChrisMCagle

My BAD! Gsedan35 was correct. Here is the exact text of the law:

So it looks like if you install the cats yourself you could "technically" get dinged for $2,500. If you take it to a dealer, they can get popped for $25,000 and you would get hit for $2,500! I don't know how strict DA MAN is on this, but I am just curious as to what happens if the new cats are "carb legal"? Considering these are new cars and don't have 5 years or 50,000 miles on them... does that count?

-Chris

SungNamZ

Chris, after reading ALL this, are you saying I am sitting here with Kinetix Plenum installed and loving it, awaiting FedEx to deliver my Kinetix Racing High Flow Cats, get them installed and then dyno and I am SOL?

JST4FN

I'm sure they are listed for off road use because no one wants to spend the money on them getting CARB certified. I'm sure all the high flow cats will pass emissions. Technically though you are not supposed to replace them until the mileage listed above is achieved.

Now the test pipes are illegal period...

Thanks Mike

ChrisMCagle

Well not necessarily.

This effects ALL High flow Cats, not one specific manufatcurer. You, along with everyone else who has high flow cats installed (myself included) will in all actuality be fine, as long as when the time comes to get smogged, the cats pass both visual and sniffer tests. If not, then you would probably just get a "no pass" and to fix it all you would have to do is replace the high flows with your stock cats, retest, pass, then throw the high flows back on until you need to get tested again.

I suppose that it's also pheasable that you could run into a police officer who is having a bad day and decides to screw with you and give you a fix-it ticket or something and make you go get your car tested because he can tell by the smell that your cats are not stock (Oh yeah... they smell like sulfer BIGTIME!).

Pheasable... but not likely.

In my opinion, you will be fine.

-Chris

orhanz33

if i got testpipes you would be able to tell from smell alone? i don't understand, if they're both illegal, then why cut your power gains w/ high flow cats (what i was originally planning on getting) and not just get the test pipes?.... unless your worried about the envrionment which i don't really think anyone who swaps their stock cats would be...

ChrisMCagle

Yes, if you got test pipes, you could most definitely tell by the smell. They have a STRONG sulfer smell. Worse than high flow cats.

Test pipes are illegal for the simple fact that they do not remove any of the pollution that regular catyletic converters do. That fact alone makes them illegal. Whether or not you are concerned about the environment doesn't matter because "THE MAN" is concerned and he makes the laws.

High flow cats, on the other hand do cut the emissions down to a legal level which in some senses makes them "legal", but unless you have documented proof that you had a problem with your current cats, it is illegal to replace the stock cats with anything. Soooo... in technical terms, they are illegal. You would still pass a smog test in most cases with high flows, whereas you would absolutely not pass with test pipes.

It comes down to how much of a pain in the a$$ you want it to be. If you don't mind having to swap out your test pipes with the stock cats every time you have to get smogged (or get popped by a jerk-off cop), then by all means run test pipes. But if you want to install them, and forget them... go with high flows.

my 2 cents

-Chris

lsdunique

iTrader: (3)

Yes, it is technically illegal to replace any converter unless it is damaged.

Our cats are CARB certified converters, but you cant replace factory ones unless yours are damaged.

In all honety this really isnt a factor because the cats still pass visual and they still pass the sniffer. Plus they come with a certificate. So the converters we use are legal, but to install them when the factory cats are not damaged is illegal.

This is really a tiny technicality of the emissions law and your car will pass smog with any of the high flow cats out on the market.

MustGoFastR

iTrader: (13)

So replace your cats ans take a baseball bat to your stock ones and say the were damaged when you ran over something, right?

Now that that's settled, which cats are the LEAST smelly? I'd like to add a set to my RWD FX35 already have intake and plenum, considering UR pully, headers, cats & exhaust), but don't want my bling ride smelling like sulfer .

ChrisMCagle

Well, unfortunately you are not going to escape the smell unless you stay stock. High flows will definitely smell less like sulfer than Test Pipes, but they all will still smell pretty funky (that's the price you pay for horsepower).

Honestly, it's really not too bad.

-Chris

2003z

iTrader: (7)

My hollowed out stock cats have no unusual smells and sound great. I went back to stock with my supercharger, on stillen's recommendation, but I truly burned one out, so my Kinetix are on the way too.

MustGoFastR

iTrader: (13)

Yeah, I guess it can't be that bad. My wife's '01 Xterra occasionally smells like sulfer when we get out in the garage (no idea why), but I've never noticed it outside or in the car and never had problems passing smog.

As long as these high flows pass emissions ok (don't really want to have to change them out before hand), it should be fine. I'm also considering modding a Nismo exhuast to fit as I have the same exhuast as a G35 coupe (just need to extent a section 8" and extend the tips).

So, if the Crawford, Kinetix and R/T cats all produce similar gains, why choose one over another for any reason other than cost? What are the weights of each? Are people really concerned with the look of the welds and such (lke you ever get down to admire them)? Do they wear out over time (faster than stock)?

ChrisMCagle

The MAIN reason I would say to choose one brand of cats over another is if they will pass a "visual" inspection. It's been quite a long time since I've had to get a car smog tested so things might have changed, but if the guy checking your car actually gets down and "looks" at your cats now, you want something that looks like stock. the R/T cats will absolutely not pass a visual inspection. The KINETIX or Crawfords will because they look pretty much like an OEM part. From what I heard, all high flow cats are pretty much the same as far as gains go, so I would base the purchase on appearance then price.

-Chris

MustGoFastR

iTrader: (13)

In that case, it looks like th Kinetix are the best deal right now; cheaper than crawfords with all else being equal.

Sharif@Forged

iTrader: (92)

The cats will not be visible during a smog check, so as mentioned previously, the outside appearance of the cat is irrelavent. As long as all your other visual equipment is intact, and your ECU isn't throwing off any errors codes...you should pass with flying colors, including the sniffer test with the high-flow cats.

However, I'd just like to deposit some additional commentary here...I need to get on soap box for this one. For those of you that are running straight pipes, I'd like you to consider something. Given that the High Flow cat flows about 90% of the volume of air of a straight pipe (Cheston posted the flow-bench tests in another thread), the only reason I would see to run a straight pupe on the street would be the costs. Straight pipes are about $200 and high flow cats are about $500. Although we are all performance car enthusiasts, we are also members of the society we live in. We should all attempt to help preserve the natural environment as much as possible. I think mods and good emissions can coexists, as demonstrate by the high flow levels of most high-flow cats. Think of yourself as embassadors of the modded-car community, and we need to be setting hi ethical standards whenever possible. So please spend the extra $300 and buy the cats...you'll be saving the environment, and hopfully keeping the feds and cops off of our collective butts. IMHO, it's not worth it for an extra few HP.