Catalytic converters replacement

Thanks for your replies. I forget the codes but it showed bad for the primary O2 sensor and cat. converter. So zI had the sensor replaced first but the check engine light came back on so I thought I'd do the next step.
Also I may have been impolite in not properly introducing myself yestiddy. My name is Mike and my Tacoma is an '01 PreRunner that I bought with 128k on it three years ago. Now it has 190k and I am still loving it. Prior I had an '88 FourRunner that had about 300k when I sold it. I actually prefer the simplicity of the '88 but I like the extra cab of the Tacoma a better.
I'll check Rock Auto before I order so thanks for input. Mike.

 

No expert here but it would probably help if you said if it was 49 state emissions or a California emissions.
(California had two converters, the rest of the country had one in 20000.....maybe it’s same in 2001 )