USDM ITR Header Selection

[CW FL5 CTR]

I am trying to buy a new header (I don't have the original) that will fit my setup. I have a Tanabe Medallion Touring S exhaust with an OEM style replacement cat. I know I need to be cognizant of the collector size of the header for it to work with the USDM sized cat. From the research I have done, it appears the OEM USDM ITR has a 2" collector. Are there aftermarket headers that are also 2" and fit with the stock cat?

[aw614]

If you can find an OG Comptech or Greddy header for LS/ITR, it would fit. Just make sure if you do find a comptech header do not get the one for the 94-99 GSR that does not have the front o2 bung on it.

I think DC sports also made one that fits too.

[CW FL5 CTR]

Thanks for the info aw614! I believe my car was tuned for a 4-2-1 header (which I'm replacing because it is damaged), what adverse effects are there with going to a 4-1 header? I guess what I'm asking is whether or not it matters if I switch to a 4-1?

[Dave7CDMTYPER]

That's correct the USDM header has a 2" collector. See here where we confirmed this: viewtopic.php?t=1835

[CW FL5 CTR]

I see you can still buy the DC Sports Ceramic coated 4-2-1, but it looks like junk IMO especially for the $475 they want for it.

The only other 2" collector header I can find is this ebay no-name header: https://www.ebay.com/itm/364785462142?f ... R-Lo8q7fZA

If anyone has an old header sitting around and wants to get rid of it, let me know!

[Dave7CDMTYPER]

If you're in need, you might have to take what you can find. There are not many options left for usdm headers.

A JDM header/cat/exhaust is much easier if it's doable for you.