running very rich = shitload of unburnt fuel comin out through the cat = burnt through cat.
The cats probably carked it as a result of the turbo upgrade.
First thing id suggest is get the damn thing tuned. Thos turbos will have completely different response and power figures compared to stock.
I am fitting these turbos also, and as a result, with the expected power figures, am upgrading my injectors and my AFM's. I should probably also upgrade my fuel pump.
So yes, before you go driving that thing around any further with a clogged up cat, get it tuned. If you get a new hiflow cat you will probably melt that through also