I just purchased a RB midpipe from a fellow member on the forum, and when I went to take the stock midpipe off the car, low and behold, it's not stock! I guess I never thought to take a close look at the midpipe before now to see what was under there. All I knew is that there was a cat on it.

Here are a few pics of it. The cat appears to look pretty good, with a resonator in the rear. No idea how old it is, but it came off relatively easy (no breaker bar/impact tools/stripped nuts) so I would hesitate to say it's not that old.

Any ideas of where this originates from? There are no obvious markings on the exterior.

 

That looks stock. Really old, but stock. I don't know of any midpipe that has that fat of a cat section or that perpendicular flange on the exhaust hanger rod.

 

Your CAT looks really clogged to me and it looks like the factory unit I pulled off only difference in yours and mine is yours is missing the CAT heat shield.

 

It very well could be clogged, but could also be the angle which I took the picture at.
I have never really noticed a significant problem with idle/stalling/power.

The missing heat shield is what threw me off. That and the O2 sensor cover...which I guess would go with the heat shield. I have never seen one without it, so I assumed it was something aftermarket. If you guys figure it's stock, sounds good to me.

Thanks for the input