How long does a catalytic converter last?

[G-Man]

I'm the second owner of a 91 E30 318i and I've owned the car since 2006. I've never replaced the catalytic converter and I have the previous maintenance records/receipts from the original owner and I can't find any record of the cat being replaced. I'm just wondering how long they last, car has 210K on it. I've ordered a new Supersprint cat back exhaust for my M42 318i and now I have found a Magnaflow catalytic convertor from the header pipe back beyond the cat where it will join up to the Supersprint exhaust. Looking for some feedback before I pull the trigger to take advantage of a Black Friday/Cyber Monday sale on this Magnaflow cat. That way I would have a new exhaust system all the way back. https://www.bimmerworld.com/Magnaflo...318I-1-8L.html

[Stanley Rockafella]

Usually the lift of the vehicle

[bmwman91]

It can vary widely. If the car ran extra rich or lean for a period of time (bad O2 sensor, AFM issue, vacuum leaks, a clogged injector, etc.) then it will definitely kill the catalyst. I replaced my stock one with a Magnaflow cat in 2008, and have replaced it twice more since then. BUT, that was due to issues with the injectors and doing a bunch of tuning causing it to run very rich. The Magnaflow cat I have in it now is going on 6 years and still blowing clean.