I'm planning on getting the carsound cat 94006 to mate up to my JDM 4-1 headers.

Does this cat already have a bung in it to mount the O2 sensor to?

 

The cat has nothing on it. It is an universal cat. Flare tubing has to be welded to the inlet for the donut/flex joint. A 3 bolt flange ges welded to the outlet and an O2 bung is welded to the outlet.

 

Suppose one already has a header with 2.5" collector. Where could we purchase a 94006 with the said modifications to bolt up to something like a JDM header & stock B-pipe? Thanks!

 

yes...
I installed one this past Tuesday.

JDM header with factory cat-back.

Send SMSP a e-mail. He will explain.

Will

 

Its all custom work for a shop to do. Fortunately you can probably scout one out for about $75 (what I paid from a distributor).
Kamikaze 4:1 header 2.5" collector > CarSound 94006 > USDM TypeR cat back

Madd non VTEC horsepower yo