What if I were to keep the stock x-pipes with the stock cats?
I will be going with a VT2-585 because I think I prefer the peace of mind that comes with the intercooler. However, I've had the displeasure of driving behind catless cars, and I'd rather not put others in that situation.
I don't mind if I'll be losing 30-50bhp because of that, because my ultimate goal is to equal or just beat an LSA-powered 6MT CTS-V in straight-line performance. With a DCT, even a VT1 kit will do that I'm sure.
So, how will smog / OBD check react to a supercharged car running on software tune and stock cats? Up here I think they are getting rid of all sniffers and just doing OBD code reading now.