So I have a 2002 Prius that I bought last October, it's treated me very well, but I do wonder if it has it's original cat, or had proper replacement at some point. I haven't had to SMOG it yet, but I do wonder. Everything seemed equally worn when I took a peak, nothing seemed hacked in or out. The car does have less than 65K miles, and looks fantastic and well take cared of. Do you guys know how I can properly identify the cat?
Visual inspection is how might be able to tell if it's original or at least oem equivalent. Good pictures and stuff can be found here: Prius 1st Gen – Replacing the Catalytic Converters As far as functionality goes, you'd need to look at the O2 sensor data. If you have even a low end scantool that provides live data, sit at idle and pull up the streams from the 2 O2 sensors. The upstream sensor (often "sensor 1" on a scanner) should be fluctuating quickly and regularly between about .1V and .9V. The downstream ("sensor 2") can exhibit some fluctuation, but should be mostly inactive.