ITRCA

I am buying a jdm dc 4-1 header. It has a 2.5" collector. Will i have to change my stock CAT to fit it???? or will it just bolt on??? Is there something i can buy to make it fit???

It will not fit your stock cat...you will have to buy one with a 2.5" collector to fit...might I suggest a carsound cat. They are the preferred cat of most Type R owners, including myself.

Not only that, the header collects further back than the stock catalytic converter. You will need one that is shorter than stock w/ a 2.5" collector. I'd recommend getting a Carsound cat through http://www.testpipe.com

So kabob, with the JDM header and carsound cat,do you then have to modify stock R exhaust, or does cat bolt up on exit side?

I need a Test pipe that'll have a JDM collector with a USDM end to it... do you think this is complicated to get?

98 CW ITR 322 wrote:So kabob, with the JDM header and carsound cat,do you then have to modify stock R exhaust, or does cat bolt up on exit side?

I'm not sure, yet. I've been having a hell of a time getting a proper-fit OBD-II compliant (yes, someday I'll go Hondata but I'm a broke bish right now ) Carsound cat from Hybrid Garage. They sent me one that didn't fit on the header side (had to angle the bolts which leads me to believe it would leak exhaust) and no hole for the rear O2 sensor. I sent it back to them in April and Dawn just now told me that they're sending me another one. Long story but she's been pretty nice about the whole fiasco

Right now, I have a test pipe that I got from testpipe.com that I'll try installing this weekend. I'm a little wary of it since it's not resonated at all (just literally a straight section of pipe with flanges welded on either end) but I'll see how it works out But if I ever get that Carsound Cat, I'll be installing that, instead.

Look at http://www.hybridgarage.com for custom made cats to fit your application for great prices. Good service too.

Does anyone sell a 2.5" cat and exhaust that will bolt up to Honda JDM header?

I'd just recommend you buy them seperately. You'll probably get a better deal that way.

Yess Used JDM at passwordjdm.com will get you a cat for 125$ and exhaust for like 350$

I did discover that you need some parts to do the OEM JDM header swap.
First you should replace the two 8mm nuts with new ones (one use only for self-locking - Acura dealer).

And second, the JDM header donut is PHAT! You'll have hell getting the nuts started on the spring bolts, so do yourself a favor and go to the Honda dealer and get two spring bolts for a '99 Civic B-Pipe. They have longer threads but otherwise are identical to your stock bolts.
Honda P/N is 18231-SR3-A22 for bolt.

Also the donut is same as an exhaust manifold donut for a Honda S2000.

Type R 98 wrote:Yess Used JDM at passwordjdm.com will get you a cat for 125$ and exhaust for like 350$

None in stock.

Trey wrote:Look at http://www.hybridgarage.com for custom made cats to fit your application for great prices. Good service too.

Out of business i guess...

I will ask Adrian. I know he is focues on Funtion 7 Stuff and not sure if the retail store is still open.