How to test a catylictic converter without it being connected to a car?

Last year I bought an 02 Honda Civic LX and this year it needs to be smogged. When I bought the car as is, the owner gave me the Catylictic converter along with the car. The thing is that he told me the cat converter still works, however is there a way to test it before I have a professional install it that way I'm not wasting time and money buying a brand new one and having that installed?

Currently it doesn't have a cat and I know that it is illegal. Who exactly enforces that? If I take it to a certified smog place and have them install the cat converter and they find that my car didn't have one since I bought it, do they have to report that to the DMV? The last thing I want is to pay an outrageous fine for not driving it with a cat converter? I don't know if it varies with state rules or anything, I live in CA.

No way top tell unless it has hot exhaust gasses flowing through it and it's connected to an ECU.

The Smog certifier's are not the DMV, they are just contractors. That means they don't issue tickets, just smog test certificated. If you take the car in, they should fix it and then send you away to drive the car for a while and make sure the engine check light stays off. At the moment the computer will be full of error codes about a faulty cat converter and so won't pass the tests.

If the cat converter looks OK, your best option is to curse the idiot that took it off and sold the car without it connected and pay to have it re-fitted. Yes if it's faulty, you will have to pay again.

It would have been smarter to insist the seller get the smog test done BEFORE you bought it. Then this would be his problem.

Nope needs to be connected and then a flow test can be done If you notice the honeycombing loosing its shape and even oval then its a really good bet its no good and to just replace it.

If the vehicle has no converter what's keeping the CEL from coming on? If there's no CEL lit does it come on when the ignition is turned on before starting the motor? Many motor vehicle inspection stations use a mirror to look under the vehicle to make sure the converters are on the exhaust system because there are 02 emulators sold on the internet that fool the computer into thinking the converter is on the vehicle.