jcook00

A local shop will install coated long tube headers with emissions on my 1996 LT4 if I supply parts. They ask me to bring two 02 simulators, two hi flow cats, and an X pipe. I called the header vendor to order parts and got really confused. The vendor said you don't need 02 simulators if you run cats. Can someone explain why the 02 sims are needed?
Does using 02 sims imply that I wont be emissions legal in Texas?

dizwiz24

What year is your car? Mines a 93 and I only have two O2 sensors.

The later cars had more O2 sensors and maybe you need O2 simulators to plug some of the holes?

If they want you to use O2 simulators in place of ALL O2 sensors then I dont think thats right. Why not use real O2 sensors?

The TPIS long tubes I got for my 93 had holes in them for the O2 sensors.

My current setup is long tube headers(no AIR or EGR) - heated O2 sensors - no cats - stock exhaust

DINO

I have a 96 LT4 with the TPIS long tube headers and all I needed was the headers and the 2 high flow cats ....

VR'92

The guy probably just doesn't want to go through the trouble of welding in O2 bungs into the exhaust. Its obviously a custom setup. You could probably just make the request for the sensors to stay in place. If he give you jibber jabber about things ask for it anyway.

Bluewasp

ODBII (1996) cars have four O2 sensors. Two up front and two behind the cats. you should use 02 simulators if you are not using cats because the rear sensors are there to monitor the cats.

sothpaw2

Does this mean, for a 1993 w/ OBD I, I have only 2 O2's, in front of the cats, and I will not need O2 sims but rather just to put fresh O2's before the new cats in the new set-up? This is for EM LT headers.

Thanks

VR'92

Correct. There is no reason (with cats or not) to simulate O2 sensors in 92-93 and really up to 95.

Perfusion

It sounds to me like they are going to be doing some custom welding, as well. The cats go in pipes between the collectors of the headers and the resonantor (or Xpipe, in this case). Here's a pic of mine.



The polished part above is the clamp at the collector. To the left of the clamp is a small portion of piping before the catalytic converter (noted by the color change). Here is another view from the rear, looking forward.



You can see here the additional pipes that are needed to go from the cats to the cat-back system. Your Xpipe would go in place of the dual-chambered resonator at the top of the above pic. As you can see, there is considerable distance between the headers & Xpipe.

You don't need O2 sims (as previously mentioned), and just make sure this shop really knows what they're doing before you let them get knee-deep into your header installation. Best of luck!

jcook00

Thanks for all the good info everyone. (Perfusion), where did you get the X-Pipe?

VR'92

That H-pipe is just the top part of the Corsa Exhaust he's got. It comes with the Corsa kit.

jcook00

Thanks VictorRussell'92, maybe this is a good place to ask this question while I have a few ears. What is the difference between X-Pipe, H-Pipe, and Y-Pipe. My installer asked for an X-Pipe. I see Perfusion uses an H-Pipe. What determines which to use?

Perfusion

My first mod was a Corsa catback system. Corsa designs their system with an crossover "H" pipe welded in place before the resonator. Factory LT4 systems have a similar pipe. An X-Pipe is much more obvious - the entire resonator section that you see in my pictures would be replaced with a piece that literally looks like a giant "X". A "Y-pipe" is something used on cars that don't have "true" dual exhuasts i.e., the exhuast manifolds come out each side of the motor, usually go through a "pre-cat" (per side", and then are "y'd" together via a Y-pipe to make a single exhuast pipe going to the main catalytic converter, and then towards the rear of the car. It'll then usually split near the rear tires to the right and left for the "dual exhuast" look, though it's not a "true dual" exhuast setup.

Hope that helped a little.

jcook00

Cool, then it sounds like I only need those pipes that connect the cats to the catback (H-Pipe) thingy since I already have the Corsa catback. Is there a part number for those pipes or is that custom fabricated?

redbullapril23

where you get those high flow cats at?
I need to get some!



ALSO:
Get uncoated and I can ceramic coat any set of LTs for only $188!!!!
this includes coating inside and out, all preping of materials, 3 yr labor warranty, and a lifetime limited rust warranty!

This should save you alot of $
and even if you get stainless get them ceramic coated
stainless is not rust proof just rust resitant!
thanks alot
your firend
Sean Blanton
slimshaby@mindspring.com
let me know!

comp

hummmmm

redbullapril23

my prob is that I can't really find high flow cats that will fit between the collectors and the resi!
and my LTs dont have o2 bungs so the extra little space is for the o2 bungs in the collectors

DINO

Random Technology High flow cats ...Have them on mine ....

VR'92

You probably ought to get those pipes custom fabricated at a weld shop. (It should be a lot cheaper than ordering them) Hopefully you already know of a good shop or you can ask around to see who does good work in your area.

Yeah don't go messing with your Corsa system its already about as good as its gonna get!

redbullapril23

how much were the random tech cats each?
thanks your friend
Sean

DINO

I don't remember exactly . I think they were about 140.00 to 170.00 each ...