CARB: What kind of catalytic converter do I need to get in Colorado?

What is your question?

I am getting confused about what level of Cat I need. My car is outside of the warranty period of being either 15 years or 150k miles. This is leading me to believe I can replace this with any well-fitting and similar exhaust assembly and I do not need to follow CARB guidelines. Is that correct? I am planning to install it myself and order one online for my 2008 Toyota Prius.

What makes this problem better or worse?

When the person sawed off my cat, hah.

How long has your 2008 Toyota Prius had this problem?

2 days