Dave, how's your test pipe working for you? I just jumped on that new one with the built-in "work around" for the o2 sim.

I'm mainly curious in terms of how much of a smell and/or black soot I should be expecting to see from this little mod.

I guess if I don't like it I'm only out $130

 

I've removed it. On that "last of the season" drive, those behind me remarked that when I was WOT, the car stunk really bad as well as the black sooty smoke. I also, found with my Fuji exhaust, the noise was just too loud above 5500 rpm.
I think you'll not have the same issues as me. I believe it was only because of my extra exhaust volume at WOT with the blower.