Always check for Technical Service Bulletins before you quote the job! You can't fix some of them until they've been re-flashed.
A Catalytic Converter rarely fails on its own. There are no moving parts and the OEM manufacturers do not require a replacement at any mileage interval as the converter is designed to last the life of the vehicle. Therefore, when a converter fails, it is usually the result of a component failure in the vehicle’s Emission Control System.
There is a growing number of alleged warranty claims on Catalytic Converters (part numbers 642525 or 642583) due to Catalyst Efficiency fault codes (PO 420) and / or the vehicle failing an emissions test, after the completion of numerous drive cycles