Get a new O2 sensor when you replace the cat, an old worn sensor can destroy a new cat
New 02s otw, trying for NGK but might have to use delphi unless ebay will have accurate parts/ not reboxed
If theft is an issue, only use the expensive cat on test days, use the cheapo cat minus the guts for the crooks to steal.
A friend of mine had his cat stolen, he replaced it, one month later it too was stolen. It is getting crazy. Time to hang cat thieves , and yes I am serious, death penalty for them, that will stop them.