pre cat

[kelly190]

I have been reading differnt threads and have
seen several regaurding guting the pre-cats.I
have a 94 3000gt n/a and have looked to find
the so called pre-cat but dont see it. I am getting
a test pipe to replace the cat but what is this pre-cat
all I see infront of the cat is flex pipe is that the pre-cat
and is there something inside it that can be removed?

thanks kelly190

[Igovert500]

Well, you don't see them (2 not 1) because you don't have them. Only twin turbo models do(I think...but someone please correct me if I am wrong). However, when looking for them normally, you would look in the bottom of you engine bay, one coming off each exhaust manifold, before the downpipe. The flex section is part of your downpipe. (which i would replace due to it's restrictive nature) if you are looking for more hp.
I suggest going to www.3sxperformance.com and check out their n/a downpipes, also a new catback, or possibly a used vr4 catback would be a nice addition, and definantly a open-element air intake(K&N or HKS). Those combined will be a more potent combination then simply getting a testpipe.
And just to keep in mind, if you put in a test pipe, you wont pass emissions if you are subject to emissions tests/or environmentally concerned, go with a hi-flow cat instead of a testpipe.
Hope this helps.

[Nesryn]

I have one on my SL... It's Cali spec and has all that emissions stuff done to the exhaust and what not....

[Igovert500]

Ok, so the SLs have one precat? I stand corrected, thanks. Well then yes, kelly, you do have a precat and it would be before you're downpipe, although, I would check with others about gutting it on an SL, being that you aren't turbocharged, you may want to leave it the way it is and retain some backpressure.
And to answer you're original question, the precat is like a catylitic converter in that it has chemicals to burn any unburnt fuel. Basically changing carbon monixide into CO2(better for environment) the precat was designed to assist the main cat, because the main cat doesn't work ideally until the car fully warms up. Therefore, the precats job is to compensate until the main cat is working properly. Again, you would have to check with other N/A owners to see if gutting it would be advantagous to you. When dealing with turbos, you want them to breathe better and it is all about getting air in and out as quick as possible. But N/As rely on some backpressure. Anyone have any opinions?

[Nesryn]

No no no.. don't quote me on saying that all SL's have a precat..... Go here http://www.3sxperformance.com/exhaust-na.asp and scroll down until you see the picture with 4 different types of exhausts (around the middle) Like I said, mine is Cali spec so it has all that BS on it, SL's from other places probably don't, as you can see from the stock fed-spec that there's no precat...

[kelly190]

Thanks guys I was sure I didnt have a pre-cat now I
know why I was also wondering how much louder will
it be with the cat removed I dont want it very much louder
if possible. and i did the K&N filter replacement
thanks
Kelly

[Hotshot8792]

this is how it goes

all TT cars are cali-spec so they all have precats

all 1st gen N/A's are fed-spec cars therefore they do not have precats
all 96-99 cars are calispec so they do have precats
the 94s and 95s were mixed between cali and fed so some have precats and some dont.

If you do have precats, it will be located right after the exhaust manifold so you wont be able to see them unless you actually get up under the car, of if you remove your front heatshield (3 bolts and slides right off) then you can see if you have them or not.

[talskinyguy]

all TT's have precats, not just some.

[Igovert500]

that's what we all said...the N/As were the question. Hotshot and Nesryn, thanks for the correction/clarification
Kelly, replacing the cat with the testpipe wont be that much louder, but if you replace the whole exhaust, you will gain quite a bit of volume

[talskinyguy]

Im going to blame my stupid responce on the 40 hours without sleep.

[Igovert500]

haha, i think we can all understand that from personal experience...