Catalytic failures on Prius

How many miles on them? I have a 2010 with 138 k on the clock and no issues with codes or cat replacement. Other car is a 98 4Runner with 255 k on the clock. That needed a new cat last year to pass smog.

What codes or symptoms were being experienced to warrant a cat change? This is not common

 

If either are in CA or NY, then the Toyota part is the only choice. (CARB rules)

In 48 other states, you can buy aftermarket exhaust systems comparatively cheaply.

http://www.partstrain.com/store/details/Toyota/Prius/Eastern/Catalytic_Converter/2005/EAST40712.html?source=gglpla&gclid=Cj0KEQjw6O-9BRDjhYXH2bOb8Z4BEiQAWRduk6FedNJsfPH26f4dpHOBvBvZHR_5fjtu0OatrlVDMY8aAvPN8P8HAQ

for under $270 (brackets and bolts needed) will replace a lot of the exhaust system with new. (other competitors exist)

At a lower price point you can try to just replace the cat itself, but I would go with the entire unit.

2004-2009 Toyota Prius Catalytic Converter - Walker 16337 - - PartsGeek.com