Ok heres my ? ... Why can a Camaro NOT pass emissions with long tubes? The only reason I can come up with is that they wouldnt have AIR fittings on them ??? I dont see how a less restictive exhaust could in any way make the actuall emissions any worse when on the sniffer ... So why wont they pass? Also, what headers provide the most noticable gains ? Header Long Tubes ? Or another brand of long tubes ?

 

In many states it is illegal to move the location of the cat(s) in any way, and most, if not all long tubes do not leave the cat in the factory location. Largely depends on how rigidly enforced this type of law is. A long tube headered car can pass with little or no increase in actual emissions (over a similar car with factory manifolds or shorties)

 

long tubes have AIR tubes, just depends on the model or style you get. and i think it has more to do with the visual inspection. i havent bother to find out simply cause it doesnt affect me. Trey

 

AS stated earlier it has to do with the location of the cats. The factory location of the cat is placed in that position because it has the quickest light-off of the cat to start the "cleaning" process. This way the car only runs for a very short period of time before the cats get up to temp and start to "clean" the exhaust. When the cats are moved further back it takes them longer to get up to operating temp so in theroy they pump out more "dirty air" that the factory location. But once they get up to temp the cats "clean" just as well as in the factory location.

 

AS&M headers keep the same cat location or maybe I'm just dreaming?

 

IF the headers have a CARB # then they have gone through the extensive testing and paperwork showing they meet the same standards as the factory in the respect to emissions. So in the case of SLP headers they are good to go, as for the AS&M I am not sure if they have a CARB#. If they do you are good to go. Alot of times guys will just get a sticker made that has the SLP's CARB# on it and say their headers are SLP and also have the cats in roughly the same location as stock and they pass the visual inspection. Don't believe all the people that say that SLP headers have a special "tag" on the header itself with it. I have a set of SLP 13/4 heades and they were purchased directly from SLP and they never had a "tag", but came with a CARB# in the paperwork. Hope this helps.