I imagine that any junk metal dealer who might be buying a lot of catalytic converters from the same folk would not be deterred from buying a probably stolen one, as they most likely are undoubtedly acting as a fence for stolen cats…
My son who drives a biggo Dodge Ram Van was shopping at a Walmart and since his van is so large, he usually parks a bit away from the entrance. He was coming out with his purchases and it was around two in the afternoon, no less, and he saw a car parked next to his van and there appeared to be someone under his van.
He figured it was a cat stealer so he started yelling for the Police and to everyone within earshot, “They’re stealing my catalytic converter, someone call the police, someone photograph the car.” And other stuff, and he stared waving his packages around as he headed for the van.
That scared the cat stealers and the car took off, but the guy under the van was not fast enough and he was left in the parking lot and he took off running.
When my son got to his van he found that the exhaust pipe was only part way cut through and the guy under the van left the sawzall. The sawzall was a cheapie and not worth much, so he took out a hammer and smashed it and left it in the lot in case they returned…
He took the van to a service station had the pipe fixed and then went and had a chain link fence cover welded over the catalytic converter so if someone tries it again, it will not be so easy…
Later, when we talked about it, he admitted he probably should have turned the sawzall over to the police as there might have been fingerprints on it, but he was too pissed to think straight at the moment…