Who's catless?

I have removed mine, and installed a straight pipe in its place!!
I have felst the diffrence, but if u have a second gen its impossible to do that cuz I think u have a sensor in the cat

test pipe ownz you

Your car is fairly new, and the new cats have not much of restriction.

Im straight piped as well.

Its possible to do it on second gens but I have to do something about the sensor. I know the flow is less restricted because it's newer, but I'm really just looking for a louder sound. I guess what I'm really asking is has anyone gutted theirs? because that's what I want to do, but then about the sensor, I suppose I can just pull the check engine light

and for the people with straight pipes, what kind of muffler/pipes are you running? how would you describe the sound at idle and higher rpms(4500-6000)?

We cant do that here in Nashville. Unfortunately, emissions laws require our vehicles to have a catalytic converter, unless they have a production year of 1976 or earlier.

AltimaDude99 said:

Its possible to do it on second gens but I have to do something about the sensor. I know the flow is less restricted because it's newer, but I'm really just looking for a louder sound. I guess what I'm really asking is has anyone gutted theirs? because that's what I want to do, but then about the sensor, I suppose I can just pull the check engine light

and for the people with straight pipes, what kind of muffler/pipes are you running? how would you describe the sound at idle and higher rpms(4500-6000)?

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2nd gens have 2 cats - 1 on the exhaust manifold (otherwise known as a precat) and a main cat under the car about in the middle. I have the stillen header on which removes the precat. I've been throwing the cat converter code ever since I did this. I consider it a false/positive reading. It's right in throwing the code because the sensor after the downpipe is expecting a certain air quality with the precat on. When you remove it, the exhaust properties change and the sensor thinks the (pre)cat is bad - yeah, it's bad alright....it's f***ing gone! I don't give a damn about the light cause my engine purrs like a kitten and rips like a lion.

hahaha well said jethro..so you're sayin its louder at idle..etc..? That's really all im looking for in doing this, a louder sound.

All Altimas have 2 cats..a pre cat, and then a standard cat. The difference is in 95 they put an O2 sensor at the 2nd cat to read the difference. 93-94 only have one O2...but everyone has the 2 cats.

Peterson said:

All Altimas have 2 cats..a pre cat, and then a standard cat. The difference is in 95 they put an O2 sensor at the 2nd cat to read the difference. 93-94 only have one O2...but everyone has the 2 cats.

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I thought you guys only had the main cat.

AltimaDude99 said:

hahaha well said jethro..so you're sayin its louder at idle..etc..? That's really all im looking for in doing this, a louder sound.

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oh yeah, it's louder and then some if you combine it w/ an exhaust. cams and a high flow cat would also.

peterson, if you have a haynes manual, check that out. I just picked one up the other day and it shows the 93-94 as having regular looking stock headers. alot different than that big bulging precat on mine (99 se-l)

No...my 94 had a pre cat. Maybe 93's don't, but I think they do.

well on the 2nd gen there are 2 cats, the precat in the headers and one underneath the shifter area. the only cat i have is the one in the headers.......so..does that count as no cat?

I have also one cat since I got my custom catback.Just the one by the engine w/ the sensor,not the one farther under the car.
Damn she sounds good though...hehe.

So I am one cat-less now

so HondaKilla...does the one under the car have an o2 sensor on it too..if so..what did you do about it?

Peterson said:

All Altimas have 2 cats..a pre cat, and then a standard cat. The difference is in 95 they put an O2 sensor at the 2nd cat to read the difference. 93-94 only have one O2...but everyone has the 2 cats.

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My car only had one cat which was in the factory header. I thought I had a second cat which really turned out to be a resonator. Go figure...

Oh, I have HS headers and then 2.5" straight pipe to crappy Arospeed muffler. Straight pipe was a good addition.

Sorry dude, but unless you or someone else did some exhaust work before you bought the car, you have a catalytic convertor under the car.

AltimaDude99 said:

so HondaKilla...does the one under the car have an o2 sensor on it too..if so..what did you do about it?

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No...the only sensor I saw was the o2 one stuck into the cat by the engine.

originally posted by CISCOKIDRB:
...I thought I had a second cat which really turned out to be a resonator. Go figure...

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The muffler shop thought mine was a resonator also...ahhaha.I had to point it out that it was the 2nd cat.

I had no cat for a while. hotshot header and a test pipe.

Hotshot header replace the whole exhaust manifold. Test pipe doesn't seem to give me a noticeable gain in power, not worth the amount of rust I ate when it is time to do inspection.