93-94 exhaust and cats (again) (1 Viewer)

Joined
Oct 23, 2009
Messages
75
Location
Encinitas, CA
Hi, I've been researching how to solve the issue of the twin side-by-side cats of 93-94 hanging so low.

This is California, so there must be 2 cat converters, which means there is no space to install them horizontally.

How about routing the two down-pipes separately: the inner one goes down inside the frame, next to the transmission, one cat goes there; the outer one stays where it is, but now there is enough room for the outer cat to go horizontal. Would this work?

On a separate thought, if I were to install the two converters in series, like in later models, they could be horizontal. Would the smog technicians know that they are supposed to be side by side for this year?
 
Last edited:

Will Van

GOLD Star
Joined
Aug 18, 2017
Messages
1,935
Location
Austin, TX
Hi, I've been researching how to solve the issue of the twin side-by-side cats of 93-94 hanging so low.

This is California, so there must be 2 cat converters, which means there is no space to install them horizontally.

How about routing the two down-pipes separately: the inner one goes down inside the frame, next to the transmission, one cat goes there; the outer one stays where it is, but now there is enough room for the outer cat to go horizontal. Would this work?

On a separate thought, if I were to install the two converters in series, like in later models, they could be horizontal. Would the smog technicians know that they are supposed to be side by side for this year?

I doubt Cali would know the cat layout. Most enthusiasts don’t even know the difference until they start installing sliders.

Your best bet is to install them in series. Does Cali do a visual inspection for the PAIR system? Delete PAIR and move your O2 sensors to the exhaust manifolds. Then use a Magnaflow downpipe with the integrated cat. You can add a second cat after the downpipe.

Otherwise I think you’re stuck with side-by-side cats.
 
Joined
Oct 23, 2009
Messages
75
Location
Encinitas, CA
Anybody has done something like this in California?
Going from parallel to series cat converters?

I've noticed that CARB categorizes 93-94 LC's as "dual exhaust", and 95-97 as "single exhaust", but I don't know if dual implies that the cats must be parallel.
 
Last edited:
Joined
Oct 23, 2009
Messages
75
Location
Encinitas, CA
Upon reading some more, I think it's hopeless.
Although I can't find a direct answer, this phrase is repeated in many CARB documents: "dual exhaust system with one catalytic converter per exhaust bank."
 
Last edited:
Joined
Oct 5, 2014
Messages
436
You can do what you want to pass inspection. 93/94 with obd1 don’t care if you have cat or not. I have a 93 and have deleted the cats and egr and everything, no cel or anything. So maybe find out from an inspection station what you can do to pass.
 
Joined
May 3, 2016
Messages
1,036
Location
odessa, tx
Also means no chance of ever selling this to someone out of state. Lol. I would think you could get around not having 2 cats and still pass emissions.
 
Joined
Aug 5, 2010
Messages
4,958
Location
Colorado
You can do what you want to pass inspection. 93/94 with obd1 don’t care if you have cat or not. I have a 93 and have deleted the cats and egr and everything, no cel or anything. So maybe find out from an inspection station what you can do to pass.
Obviously not from CA ;)
 
Joined
Oct 23, 2009
Messages
75
Location
Encinitas, CA
It's a toss-up I guess.
Besides passing the gas test, they are supposed to do a visual inspection, cats must be in the right number, location and type. They don't always check so closely, but sometimes they do!
I know cases of getting screwed in spite of passing the sniff test. Of course my friend wasn't very smart taking his cars to the smog technician training center, so obviously they were anal (in more than one way.)

I have found the Magnaflow 3391004, which is smaller than most California cat converters and maybe two of them can be tucked high up in the standard location, but not without some careful exhaust work.
 

Users who are viewing this thread

Top Bottom