Just ordered a catalytic converter. I'm going to attempt to replace it myself. I watched a couple of videos and it seemed like I could do this. Of course, that is assuming that nothing goes wrong.
I texted my buddy to be standby. I'm sure he won't be happy to read that text in the morning! Also, texted my shade tree mechanic (fully certified). I want to pick his brain. But then decided to go for it. Did not go with a cheapie part. Got the brand name one that cost 4 times as much. Still a lot cheaper than Toyota OEM.
I swear I heard a difference in exhaust sound a year ago. Shade tree guy (and his buddy) both said it sounded fine for a car its age. Been rattling the last couple of months. I'm pretty sure that early noise was the catalytic converter.