vioswhite

my 90LS have been removed catalytic converter for a long time.
now I want to fix this to make fresh air.

Is is important to do this ?
thanks guy

hobojoe

well im not for certain but on the gen 1's up until 91 at least I know since it was the case with my car they had 2 Cats.

trukn1

The gen's come with 2 cats,, one on each side of the motor and then pipe down into the Y pipe. In most states, it is actually illegal to not have a catalytic converter installed on your car and will, in most cases, most assuridly fail inspection/smog tests.

hobojoe

Lucky for me good ole CO doesn't have emissions testing anymore

SCrollinSD

if you have a personal or moral conviction about running rich emissions, then yes you should fix it. likewise, if you have not yet smogged or emissions tested your car, you will more than likely fail without the cats.

that said, theres nothing wrong with running straight pipes, test pipes, or whatever setup you have from a vehicle functionality or reliability standpoint.

FYI global warming is untrue, so don't worry too much about the polar bears, if that's what this is about. :P

JBrady

I am not certain of the laws in California but it seems that California delivered 1990-1995 LS400s had 3 catalysts, one attached to each manifold and one after the Y. See attached picture.

I would purchase two metal substrate core, round bullet type catalysts and have them installed one on each exhaust manifold. This will not reduce power and may well increase torque.

Since your car currently does not have catalysts it may no longer have the support bracket seen in the picture that bolts to the bottom of the tranny bellhousing and supports the weight of the catalysts and is part of the exhaust support system. If you do not have one it is worth getting.

PureDrifter

iTrader: (10)

This has been debated to some length on this forum and it was discovered that there are multiple part numbers for the y-pipe, with one being equipped with a catalytic converter, and one not having it. for some reason, certain LS400s have a center cat. BUT, most that have looked underneath their vehicles have discovered they do NOT have them.

JBrady

Yes, most do not have a third cat, I believe it was only California cars and even then maybe not all years? (90-94). As I said, since I do not know the CA law it may require the car to be as it was delivered IF it was a CA car originally. If it was delivered in another state as a non-CA compliant car it would likely be legal with the as delivered two cats.

vioswhite

so is it worthy to do this ?

many friends of mine said that I have not installed this... it's nothing

SCrollinSD

^^ we have pretty much answered your question already man. "worthy" is subjective. if you already passed smog and have the car registered, theres no pressing need for you to do it, no.

iamviolet

besides isnt there more power without them?

Kaydee

but your clothes stink more without them...I will be putting mine in soon enough.

PureDrifter

iTrader: (10)

on an old honda or toyota with crappy cats, this is true.

but the LS came with factory metal matrix cats, which will actually outflow most high flow cats. de-catting isnt really worth it for anything less than a flat out FI build, and even then there are super high flow race cats that are usable.

LEXUSA400

This picture is what the center section on my '97 looks like. Is this correct or has someone been doin' some changing around?