Code P0420 in NY - Can I buy a used OEM Cat to replace it?

You could have this Cat shipped to a friend in a different state: EPA Catalytic Converter for 2004 2005 2006 2007 2008 2009 Toyota Prius 1.5L L4 | eBay It might not pass the visual inspection in California, but maybe in New York they're less strict if they have to remove a cat shield to do the visual inspection of it?

The noise is probably coming from the flange gasket failing between exhaust manifold and Cat pipe because the cat is clogged and creating back pressure. You could try a cat soak recipe and try to get it cleaned out and working again?

As for a used one, maybe you could get lucky and pull an OEM one off an old Prius, but buying a used OEM online will probably not go well, because they're super valuable. As in look at the precious metal prices for 2 grams of Rhodium, 2 grams of Palladium and also platinum and you'll pay more than that for a used OEM cat that might be clogged or soon will be clogged.

 

I'm not sure what the standards are in New York anymore If you have a missions but parts aren't missing critical In other words you're allowed to replace crap that isn't working with parts of equal quality made by whoever if you can get away with that then you're in good shape these cheap cats can get you through a year maybe two maybe a tad longer You got to shop carefully and buy the brick type converter not the fine wire or whatever it's called they just burn up immediately or pretty quickly

 

Maybe we could get the metal stamp of the Toyota logo they use to identify OEM cats?

 

I'm sure a tool making place Forge shop whatever could whip one up directly All they need is a picture.

 

You can spend about 300 for a bolt in walker and never have a problem, buy a walker EPA cert universal for 200 and spend 100 to have it installed(welding ends on to bolt in) or buy a junk aftermarket one for 100 and have issues in a year. Sorry, but I have seen such crap on the market for supposedly oem spec parts lately it just isn't worth being thrifty if you want to keep the car. Crap knock sensors, throttle position switches, struts, rotors, wheel bearings all parts I bought and had them fail in less than a year. In some cases they were obviously so badly made they went back right away.
If you check your state rules I bet that all the cat needs is the EPA number stamped on it, not a toyota logo.
Also, do the install yourself or tell the shop you want the old cat back. They are still worth a few bucks to a recycler.

 

Is the exhaust leak making the sound and causing the P0420 ? Also any oil consumption?

 

The Walker does look like a good option if it's 300 bucks then it seems reasonable and will get you through what you need to get through and Walker usually doesn't fool around that's the magna flow people so they're not usually looking to make junk generally speaking.