I've had a few sets of the Corsa exhausts. In my snobby opinion the earlier sets were better. The early sets were TiG welded and beautiful, the later current sets are now all MiG welded. Like everything else the price has gone up. I paid $1400 for my last new set four years ago. The cats should be fine unless they were on a supercharged Viper. Many of the Roe installations were tuned rich and caused premature meltdown of the matrix. Random makes/made metal matrix and ceramic matrix cats. The Ceramic cats are cheaper and don't quite stand up to improper tuning as well as the metal matrix cats. Either way, if the car was basically stock and yours is as well you should be fine.
One other thing, the Corsa exhaust is available in the factory 2 1/2# tubing size as well as 3" tubing size. The cats should probably be sized the same, but really don't have to be as you can use reducing or expanding cones. I've got picks of just about every combo in my gallery, as I've changed exhaust sizing and combo's with mod changes. I'd offer $1,000 but that's just me.
The offer just came out of nowhere on a trip I was on from a guy that approached me at the car wash. Thanks for the info Jon!!! We'll see!
