How long does a catalytic converter last?

Legally I believe IIRC that they're supposed to last at least 150,000 miles, or something like that. That may be an average, not a warranty. But in reality it could be anywhere between a few thousand miles and half a million. It depends on how you drive your car, the oil you use and the maintenance you give the car.

The Cat will last longer if you (in no particular order):

• Use the car used only for long trips.
• You change the oil often.
• You don't use high zinc oil.
• You live in a warmer climate or have a heated garage.
• You stop or prevent the engine from buring oil (keep an eye on PCV vavle, for an example).

Generally with Toyotas the catalytic converter fails at around 180,000 to 220,000 miles with people who don't change their oil every 5,000 miles, which ends up seizing the oil control rings which damages the cylinders which makes the engine burn oil. People who change their oil every 5,000 miles may get double that.

 

Until someone steals it

 

^ That. Theft should be your primary concern, at least with a 2008. Those are in demand.

 

The catalytic converter is covered by the emission contro;s warranty.

The California Emission Warranty. This warranty is in effect for 180 months or 150,000 miles, whichever occurs first, from the vehicle’s in-service date.

• For Prius vehicles sold, registered, and operated in states other than those listed above, and for Prius V vehicles, this repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle’s in-service date. •

 

So as far as the OP's question is concerned, the Catalytic Converter was covered by the emissions warranty.

 

Just to be clear- the metal in the catalyst is still valuable even if the catalyst isn't working due to coating or contamination.

...point is, if you pay to replace it don't let the shop just take it away. You should get something for it.