I am getting a DC JDM 4-1 header and I want to run it with a stock cat with a flange on it so it will connect up to the 2.5 inch collector. Some of you are going to say why not just get a high flow cat.....Well I dont have the money and why spend that much money on a cat thats going to fail in 6 months......But anyways what I am wondering is anyone with this set up, did you have to have the cat cut and then have the flange welded? What was the process to get this fit? Basically Im looking for fitment issues and possibly any measurments I may need. Thx

 

BTW I have a 99 LS teg

 

if your going to stick to a stock cat, i would just get a 2inch collector header. And i doubt you can make it fit,. If there;s a way, i think its not worth it.

 

My buddy said he got a reducer flange welded onto his stock cat and it worked fine but hes got a civic and different dimensions than me. Cost him 40 bux

 

someone had to have done this

 

i got a carsound cat on ebay for 40. you should just get one if you get the dc jdm

 

get a high flow cat with 2 1/2 or take it out and have made a special hole for your o2 sensor!! it's useless if you don't do any of these!!! you won't feel the power if you have a stock cat!!!! feel the 4 banger!!!

4 banger rulz!!

 

You're going to restrict the header so bad man! Why even bother? But here is my OEM GS-R cat modified to fit my JDM ITR header. I used this for smog purposes. They just cut off the stock flange, welded on tubing, put on the 2-bolt flange, then flared it.