I have heard people say that this will clog up my cat, because it needs to get air, is there any way to prevent this? Can't I just unplug the the pipe so the cat still gets air?

 

if you have an aftermarket exhaust and headers, which i am guessing you dont but, it would be fine, also you could get a hi flow cat. i am not sure about the clogging right now though.

 

Well I already have a high flow cat, but it still has that tube going into it so I'm guessing it needs air or else it will eventually get clogged.

I want to keep my current cat becuase I will need it when I eventually have to go through smog, and I hook all my emissions stuff back up.

 

Another urban myth.

I didn't hook up the A.I.R. pump after the mods in the sig, which were done right after I passed emissions testing. I hooked it back up after 2 years of daily driving when the next test was due. It passed the enhanced dyno sniffer with flying colors.

 

Over time a cat can clog if it is intended to function with an air tube. It only gets air on startup and cold situations but all those small increments of time can add up and slowly choke off your cat. A cat that has that tube needs it to complete the combustion as fast as possible in cold situations. It all boils down to cat brand, state of tune, and the amount of mielage and environment you use your car in. I have a capped cat and it runs fine. So does my buddy. However I have seen other guys cap thiers and have it clog a month later.

 

The only way a cat will "clog" is if the combustion is rich, or raw fuel is getting dumped into the exhaust (such as a mis-firing cylinder). What basically happens is too much of the fuel oxidation (you might call that "burning") is taking place in the cat, overheating it, and melting the matrix.

A.I.R. or lack of A.I.R. is irrelevant.

 

Well for now I'm just gonna leave it capped off. If the cat does clog though, how will I Know? Will it be a sudden thing? Or will it be something that gradually happens over time?

 

You will slowly lose power over time and your car will have a tough time reaching high rpm's.

 

So your saying that I will have to get a cat that isn't setup for AIR right?

But if I have a cat that doesn't have AIR will I still be able to pass the sniffer in a smog test as long as I have everthing this else hooked up?

 

You should still be able to pass as long as you have a cat in place. I don't think I can recall anyone not passing for just removing air alone. I just know that cats are desinged to run with the AIR tube if they have them. The catylist won't do its job if the necessary 02 is not in there. The stock ones aren't as are prone to clogging but aftermarket ones are finiky. But like I said, I have mine capped and so does my buddy, both of which show no signs of clogging. Studying IC engines over the last year with the focus on emissions has only really taught me how all thing stuff works.

 

Okay shifty, I'm gonna take your word for it. I hope I pass smog.

Thanks for the info

 

If you want to maximize you chances for passing emissions testing, keep the A.I.R. on there and functional.

 

I see the topic is shortys headers. I am restoring my 84Z and I want to replace the stock manifold with headers to get a little horsepower out of the motor. I am doing a complet rebuild on my 305 H.O. . Iknow, I know put in a 350. Fact is I dont want to. I like to keep the car semi original. Anyways, as most of you know my stock manifold has the "air pipes"---lack of better term that screw into the manifolds. I have done some checking and see that some companys sell headers with these air pipes on them. I do not want to have to deal with emision proplems and don't want to tear a bunch of stuff off my motor. MY quetions are. What are the headers that are good for my car that won't cost an arm and leg to purchase, and is my y pip that is on my car now any good for the install. It is fairly new and I hate to scrap it. Thank you all for you time in reading and if you can help please post. Thanks

 

I must have clicked an extra click thought I was in the header thread