OV9

My google-fu is not very good on this topic, seems a simple question, but struggled to find anything useful.
The question stems from me wondering that as my Audi hits 170k miles on the original system, if the cats are actually still doing anything useful ?
I am trying to look for objective measures, all I have found in subjective comments with no backing of any real data.
I know that actually catalysts do not get consumed during the reaction and its other pollutants and particles that cause a catalytic convertor to age.

Until they fail an MOT.

Way too many variables including how the car has been serviced and how it’s driven.

They work until they don’t

Depends where you park.

They’ll work until someone nicks them

Quite.

Someone has said e36 m3 cats are worth £600+

Tempted to stick some £100 eBay stainless decat pipes on mine and leave the originals sat hidden in the shed until they’re needed for the mot

Fwiw, 51 reg Passat 1.9 tdi still passes mot with its original cat @300k miles.