OK, well, I have had my EVO for about three weeks now and I am looking into an exhaust system...curently waiting for the TXS Turbo back...but in the mean time, how do you guys pass emissions with no CAT? Do you plan to swap out exhaust systems before being tested? I am just wondering because it sounds tempting to receive more power without a CAT, however, I don't want the exhaust to be louder...or whatever else.

Sorry if I don't know enough on CAT vs. No CAT, but if someone would please let me know the benefits of each and if you can or cannot pass emissions without one....

Thanks a lot!

Clint

 

find someone that you know that can pass the smog test for you ;P

 

Or u can just put back your cat and do the inspection and remvoe it again. Only takes 4 Screws not much work honestly can be done in like 15 mintues ?

 

I know what you mean. I am holding back on modifications until I can find a tuner who can produce valid results with a working catalytic converter. I hate it when people say that they produce their dyno results with a test pipe. It is cool when people say they have a full 3 inch exhaust thinking that they also have a 3 inch cat, but in reality they have no cat. Why is it that modded Corvettes and Vipers can produce 600-900 hp with cats and run 10's and pass emissions AND do it on pump gas? I'm sorry, I am an import fan, but I do bring up a point.

 

i agree with jinu just put back the cat but make sure you buy some new gaskets.do this a week before the smog so it wouldnt look too obvious but you wouldnt have to worry about this since its 4 years before the first smog check then after that it every 2 yrs so no worries for now.
p.s. just watch out getting pulled over if the cop sees you got no cat=chunky fine and a ticket.

 

So is the sound of the exhaust louder? I agree with inariv, in that, most of the tests done on turbo backs are with test pipes, it would be cool if they could do both...but oh'well!! If anyone has any further thoughts on this matter, please let me know. Thanks again.

 

In some state, they don't really care about emission. Then, you will not have any problem.

I really don't like the idea of removed and reinstalled the cat back and forth. Eventhough it's only 4 nuts/bolts. Car around NE area can rust easily. I'll bet you wil have a hard time to remove the bolt after some period of time.

 

1) There are NO emissions tests in Pa.
2) The system you want already exists. Buy a Buschur Turboback exhaust with a 3in cat. Its a flangless exhaust so you don't even need to unbolt the exhaust! You want your test pipe in to go to the track...I have a lift so its a 5-10minute project! Plus the flangless design works better and costs less...any questions?

And BTW...go to the LS1 boards, 80% of those guys running "10's" aren't running street legal exhaust systems and the 10 second passes are usually tuned for race gas with nitrous. (In reference to the 427's with nitrous) I'm sure people have ran 10's on 91...but not many and most don't have cats.

 

As Ive always said, there is no place in an exhaust system for kitties.

A catless exhaust will produce an excellent sounding tone, and give you a quicker spooling turbo. Ive never had any cats on any of my turbo cars. When emissions time comes, simply slap the the middle cat back on. Simple.

 

5StarSuzuki there is emmissions in PA!!! There are a few places thou that dont have that, but not everywhere in pa is liek that. I know cause i freaking live on the wrong side of the highway, if i was on the other side less then a miles distance i woudlnt need emissions, but since i'm on the side in a different county i do need it. O well, i'm still takign off my cat!!

john

 

I know that not having a cat will improve performance, but do you really want to be spewing nasty stuff like CO, NO, NO2, etc ? Exactly how much improvement do you see, and how noticeable is it in a car with almost 300 hp already?

I can definitely excuse it for racing events, but for daily driving? It's a free country, and you can do what you want (as long as it doesn't violate your state laws). But at least keep the cat on for day-to-day driving. Just because it's legal in your state doesn't make it right (your state legislators are probably a bunch of drunkards anyways).

If you'd like to find out what a cat actually does, check this out:

http://auto.howstuffworks.com/catalytic-converter.htm

 

And if you just want a really loud exhaust, just take out the muffler and the resonators and voila!

 

I agree.

but there are other solutions to your problem. you can always hollow at your cat and put it back on. thus as far as the emissions testing is concerned you have a cat, it's just empty.

 

Hollowing the cat still means you're spewing noxious fumes to the environment. Some states do more than just check that your cat is there.

 

It helps when they have like 8.4 litter engines