There are zero gains from the so-called "Sports" CATs over functional stock ones
Consider stock C7s, base to ZR1s, they all use the same CATs, so clearly they do not reduce performance
to what the Z06s and ZR1s output
Here in the USA, any legal CATs must have a CARB sticker on them to be considered legal
If not, then IF a smog shop does a visual and sees they are illegal there is a $10,000 fine and vehicle
is labeled as a gross polluter
I have done chassis dyno tests with my '99 C5, with and without the CATs and zero difference in performance
If no visual is done, being I designed my 3-inch exhaust, I choose to swap the CATs with an X-pipe
and then tuned the PCM so not error codes trip and on-board smog tests pass as if the CATs were installed
Here, though, most counties do not even do smog testing anymore as tests shown newer vehicle designs are very clean in exhaust makeup