OP: First awesome write-up!
I plan to do the same thing and wanted to ask you a few things:
a) What rear muffler are you running?
b) IF stock how much increased sound did you get by removing the secondary cats and do you think you gained any power?
c) I'm debating right now to gut the cats or just cut them out since I'm not too worried about the visual part. Would the final effect be the same?
d) If you are running an aftermarket rear muffler, what brand and how's your sound before and after gutting the secondary cats?
Kudos great job, I want to try this before spending $2k+ on a pipe as I prefer to dump that into my Brembo's