Oldblue

I’m going to say, that’s not happening!

PulpFriction

If you google "header paint" you'll find a plethora of coatings that claim to be good up to 2000F or more.

donbrew

The cat can get up to 2500 F under load. Engraving is a better solution.

Oldblue

I’ve used header paint over the years, they all melted off eventually, VHT was pretty good, makes a better caliper or brake drum paint.

greg8453

Do you really think marking the cat with paint or etching will stop a cat thief?

Oldblue

Nope. With today’s battery powered saws and cutoff wheels, just cut the studs and two bolts , you’re done! Oh! The O2 wires. They just sell the cats for the scrap value, they aren’t worried about a little damage

RJ_RS_SS_350

I did hear a local news report that the police had arrested someone after a traffic stop. Among other things, they had a stolen catalytic converter in the vehicle. If it was marked with the owner's information, they might eventually get it back.

donbrew

The stealing of catalytic converters from Prius is rampant. The HHR cat is pretty well inaccessible without removing the entire downpipe. The OP was particularly paranoid, but I think if you bother to read the first page you will find our advice is basically "don't worry".
I even saw a report of a box truck full of stolen cats, mostly from Hybrid EVs and big pickups at a traffic stop.
Since it is illegal for a shop to install a used cat they go to "heavy metal" recycling. I asked how much I could get for my old cat, was told maybe $15, not worth my time going to the recycler.

PulpFriction

Crackheads steal the brass caps off standpipes for $1. Which is why the new ones are plastics. They'll do $40,000 worth of damage ripping copper plumbing out of a house for $75 in scrap. It doesn't have to make sense.