Does this look like someone tried to get to my cat converter

[SPC4Runnergirl]

A few months ago I had misfire code p0306, I changed all 6 spark plugs and after clearing the codes and driving I got a code PO 430 for the catalyst system efficiency below threshold Bank 2. Shortly after as I continue driving for a few weeks I kept hearing a rattling sound from in the back of my vehicle and it just continued to get worse until finally my friend jacked up the vehicle and got underneath and noticed that the resonator was just hanging so he just took it off cuz it was pointless and I figured that's why I was getting that code so I've been driving without it for about 2 weeks now and last night noticed this weird misfiring action almost like a rumbling as if I were driving over those things that are on the shoulder of the road and so I ran the scanner again and now I'm getting po 304 code. My question is will I have to actually the first one is by these pictures does it look like somebody tried to cut it off or is it just normal wear and tear looking and second me having that off and driving without it for a few weeks could that be causing the new code of po304? Any suggestions or opinions will be appreciated thank you

I forgot to mention that I have a 2005 4Runner limited with a little over $230,000 MI

 

[Hungryhawk]

I see what looks like an old partial saw cut close to flange? Perhaps some shop started a exhaust pipe repair then quit? Very strange.
How long have you owned your runner?
Did it have a noisy exhaust?
I do not think a cat thief would line up his saw blade so even to a flange-usually theft is a hack job.
Does your State have smog laws