Well, I have spent hours reading through posts and have found different answers, so if you all that have put aftermarket cats on their headers don't mind, please post here what cat model number you are using. I have an OBX header and M7's new exhaust on order and I want to keep my factory system in tact, so I need a new cat. Just can't figure out which one. I am going to pay a local shop top put the header and cat in and I will do the cat back work. Thanks for the replies!

 

Check out the Random Technology metallic race cat. I don't have a link, but scobib (NAM member), was going to use one for his own custom header project.

 

Check my OBX install here. I used a magnaflow high flow cat.
https://www.northamericanmotoring.co...&highlight=obx

The cat doesn't come with 02 sensor It's threaded so just use the stock sensor.
It's the magnaflow 94136 single 02 boss.
I got it from http://magnaflow.performance-curve.c...PROD&ProdID=90
Cost me $65.00 plus ship.

Measurements are as follows
Detailed Description MagnaFlow Catalytic Converter
High Flow
Stainless Steel with Aluminized Heat Shield
Universal Replacement Converter
Dimensions:
Body Length- 9"
Overall Length - 13"
Body Width - 6.5"
Body Height - 4"

I had to cut about a half inch off each end of the cat. Since I was going into the 2.25" stock exhaust I had a flange made by a muffler shop cost $11.00. I made it a slip joint with clamp instead of welding it so I would have some adjustment room.
As others have found out, double nut the spring bolts.

Had this on since Feburary and no problems. Sounds really good.

 

btw, I got a quote on this cat: $230. It's part no. 141-25000.
I'm looking for a cat for my Megan with a bung that is in the right place...anyone?
cheers,

 

I never said it was a cheapy. It is, however, a great cat from all that I've read.

 

do aftermarket cats pass emissions testing?

e.g. function identical to the stock cat but lower back pressure?

thanks


_

 

I decided to weld the factory cat to the OBX header. So.. We shall see how it turns out. Thanks for the input!

 

Pardon my ignorance, but is there something wrong with the bung location of the Magnaflow cat listed in a previous post?

 

Having read posts by people with Megan headers who put CATs on, it seems that if you put the CAT "flat" (It's oval in cross section) the bung places the o2 sensor very close to the body/heat shield. I was thinking of twisting the CAT a little, so that it doesn't sit flat, just to get a better bung orientation. Will see this weekend when all arrives via Brown...

cheers,

 

Bung orientation is important, be sure to use some antiseize also.

 

Well, the header is on and using the factory cat. Sounds and looks great! Now if I can get them to ship me some exhaust, I'd be set! :-)

 

I installed the cat so that it set "flat ". That puts the 02 sensor pointing up into the corner of the heat shield tunnel.
It is very close to hitting the shield. I took the handle end of a hammer and pounded out a small indent in the shield and that gave about 2" clearance from the wires to the shield. I have hit some pretty good potholes and have had a lot of weight in the car and have not had any problems with the sensor hitting the shield.