[LuvMyRide200sx]

Ok this is werd!!! today i went to change my catalic converter cuss i thougt it was cracked but when i took off what i thought was the cat it turned out to be second muffler??? or as the muffler shop called it a resanator!!! it was right where the cat on most cars is (in the middle under the car). anyway my queston is if thats not the cat then where is it?????the only other thing i can find that even resembles a cat is like right where the header is rght in front of the engen!!!! but if thats it then what happens to it when u get headers???? that kinda contradicts what everyone is saying about remving ur cat??? aaaa im confused haha thanks to any who reply!!!!

 

[omega]

if i'm correct that is only true on the 98, or something odd like that, yea the cat is built into the stock header so to speak, I think you end up replacing that resonator with a hi flow cat if you get a new header on your car, but I think 95 to 97 is different, there are a couple of things different between the 95-97 and the 98 in terms of sensors and what not

 

[shane]

Yeah, we've got a close-coupled cat on our '98s. I believe they did that to reduce cold-start emissions. Either way, shitty design for performance, especially since the stock header has the exhaust ports paired up (1&2 dump into one collector, and 3&4 dump into another).

 

[V i V i D 200sx]

95s have close-coupled cats too. it sucks, cuz headers is one of the most bang for the buck performance mods, since the stock header design is so poor. but in order to take advantage of aftermarket headers, you have to get an SE-R or equivilent cat and custom install it onto your exhaust system. so, the best thing to do, if you can afford it, is get headers, replace the cat and get 2" straight piping w/ a nice muffler all at the same time.

 

[omega]

don't you mean header, being as it's only four cylinders?

 

[PatScottAKA99XE]

Haha, this same issue turned into a big mess on the Stromung GB thread.

I havent sorted it all out yet, but with the help of Greg V at Mossy Nissan(Thanks, man!), we got some of it fugured out, sorta..

SR20 cars:
One cat, under car

GA16 cars(OBD II): BIG MESS.
Some have one in manifold. Mostly Fedral emission package cars.

Some have 2, one is part of the manifold and one is under the car. Mostly California emissions cars.

The ones with one cat(manifold) have a resonator under the car. The ones with 2 cats dont have the resonator.

About headers(GA16):

If you have only the manifold one, you need to get a cat to put behind it, and relocate the down-stream O2 sensor behind the cat. Best bet... Get an under car cat from a dual cat car(read below)

If you have 2, toss the manifold one and use only the second one. The header should bolt right up to it. You still need to relocate the second O2 sensor.

Of course you could be dumb like me and toss out the second cat when you made 2" manifold-back exh for your car. Me stupid! Now I have to go buy another one to build my new system.

Please dont run without a cat, you will gain no noticeable power (1-2 hp)and you will be a polluter.

 

[evilharp]

GA16 cars(OBD II): BIG MESS.
Some have one in manifold. Mostly Fedral emission package cars.
...

If you have only the manifold one, you need to get a cat to put behind it, and relocate the down-stream O2 sensor behind the cat. Best bet... Get an under car cat from a dual cat car(read below)
...

Please dont run without a cat, you will gain no noticeable power (1-2 hp)and you will be a polluter.

My '98 Sentra E has this as well. Apparently, all Canadian Sentra's/200sx's (with the GA16DE) got the Federal Emission's package. It may suck for power, but the cat lasts much longer than the under-car variety (no road salt to worry about, better heat gain, no worries about condensation in the chamber, etc..). And for the "Fart Pipe" crowd, you can run a straight pipe from the Manifold back (or out the side like them V8 folks) if you so please, as there is no post-manifold cat to worry about .

And think of it this way. The zero-emission California B15 Sentra has 3 cats to contend with!! It could be worse .

 

[LuvMyRide200sx]

so they put a aftermarket cat on project 200sx SE turbo ?????? I dident see a wright up on it!!!!

 

[myoung]

so they put a aftermarket cat on project 200sx SE turbo ?????? I dident see a wright up on it!!!!

we installed a Random Cat a long time ago... look back on the Project homepage... same article as the HS header install.

The Project car is a 1998 CA model,,, had 2 cats.. Federal models have a resonator under neither. Both have the close coupled cat built into the exhaust manifold.

hint: The stock Nissan cat that came on CA models in 98 and 99 are excellent.... if you can get it cheaper than a Random ..go for it.

 

[LuvMyRide200sx]

Thanks for all the imput guys!!! God i dont know how i ever lived without this forum before