Redleg

I know that changing some things on your exhaust (taking cats of X/H pipe) violate emissions. Do Long Tube Headers do the same thing? I was browsing, JBA's site and they say their LTHs are off road use only. Can anybody explain the science behind this one?

Menace

I don't see why they would change your emissions unless you removed the cats? The high-flow cats might increase your emissions. I'm no expert on the subject though.

Boostaddict

I believe there are no Longtube Headers for the 05+ GT that are CARB legal. This means that if they aren't CARB approved you may not pass emmisions depending on how strict the state or county you reside in is. However you may be able to pass emmissions in stirct states with a catted setup as you have a good chance of passing the sniffer test and some states just do a visual for cats. This is why though JBA and other header companies say offroad use only because without a CARB approval they have no way of saying they will pass for sure.

From our experience we have lots of customer though in California which is a very strict state that run Longtube headers not only on their S197's but also Cobras and GT and I haven't heard from any of them having a hard time passing emmisions. Again. It really comes down to how strict of an area you live in and who's doing the inspection. Hope that helps. Jared

hawgman

That's because California doesn't have to have a state inspection for 7 years from the time of purchase.

As for the original question. Technically installing LTs will indeed violate emissions laws. Any modification to the exhaust system ( including relocating the position of the cats ) will violate the law.
But that does not mean that your car will not pass a sniffer test.

In Texas for newer cars they do an OBD II scan for inspections. For whatever reason the place I went to could not get their scanner to communicate with my PCM so they did a sniffer test instead. And here the sniffer test doesn't just involve putting a probe in the tail pipe and letting the car idle. They actually put it on a set of rollers and take several samples at pre determined RPM and speeds. I am running Kooks LTs and high flow cats and my car passed the sniffer.

failurze_art

yeah right now I am trying to decide between the kooks, dynatechs, and stainless works complete systems. I have talked to the folks at all their offices and they say if I get the x-pipes with cats that I will be ok with emissions(all the systems come with o2 sensor wiring). So I don't think long tubes matter.

tonkpils555666sas

we are good in Maryland... camaro's and trans ams with full exhaust systems pass emissions by leaving the cats on... i would say that you will be fine if you purchase longtube headers (if thats the intent of asking this question)...

Redleg

Thanks all for the replies. So it sounds like in a nutshell:

1) Theoretically, modifying exhaust will violate emissions
2) It all depends on how strict the state is.
3) Possibly, so long as I have my cats I should still be good (if my state just does the visual inspection for them)

I'm a Illinois resident and I think the inspection is just a visual cat. Thanks Lethal Performance for the response. I'm on the fence between the Mac Prochamber Catted H Pipe with Long Tube Headers or the JBA catted H pipe with Long Tube Headers. I've just heard from some sources that the Prochamber catted H Pipe is out of production until Mac finds a new manufacturer for their high flow cat.

We'll see.

CrazyAl

Wow, this is the fifth thread about this in the last week or so?

Anyway:

In the USA, NO longtubes are street legal. They all violate the Clean Air Act (a FEDERAL law), becasue they move or replace the OEM cats. The law reads that you cannot replace or move the stock cats, period.

Section 203 of the US Clean Air Act, 42 US Code, Section 7522

Anyway, practially speaking, that law isn't particularly relevant. What matters most is your individual locale's inspection policy. Some places are stricter than others. But so long as you have cats you can pass a sniffer test.

iwannagofast

go to the shadiest place you can findand offer the guy doing the inspection 50 bucks.ive had to do this a number of times with other carsit should be fine

Iwasaricer

this is kinda off topic but from what boostaaddict said.. is it true that if you don't get any aftermarket installations "approved" by the CARB then if they find out, they can impound your car?