I just got back from seeing Andy at ADM Performance. He recommended going back to stock cats, so I did. I have been having intermittent CEL (P1153 codes) and don't want a tune yet. I tried fixing myself, and took it to a muffler shop too first, but the CEL was still intermittent. Andy has some nice cars in his shop right now, but took the time to fix me up. I also met another camaro 5 member - flomocamaro - while there - he has an awesome car.
Sound is now quieter without the hi-flo cats, but that will make my neighbors happy.
Jerry - pm me if you are interested in the hi-flo cats. Waiting to see your new wheels!