Catalytic converter stolen what to do

1) Yes. Car will NOT be happy.
2) NO, b/c of exhaust gasses entering the car. Have you heard of carbonmonoxide?
3) YES. Car will be loud, not sound right, and warning lights will be displayed.

 

Mostly, this is a California issue, CARB only allows approved cats, none are approved for the Prius but Toyota's. ($1600) In the other states, you can buy an aftermarket cat for under $400.
So, in the US, California is the prime theft area

 

where are you locate?

 

I'm thinking #2 is "your car will be like a 1960s car without a muffler." Not much real danger of CO unless you idle in a closed garage. Probably MUCH more dangerous to NOT drive out of the area where your cat just got pinched (unless it was from your own driveway). I certainly wouldn't want to be unexpected trying to hike out a area after being hit with crime, and wouldn't want to leave my car there either.

PS-Last time I reported a stolen car in Oakland, they said nothing would even be "in the system" until I could wait for several hours or DAYS for a cop to respond and "take the report". AFAIK, accept for putting a "see person about theft report in 120 Maple Lane" on some cops list, there was no other support.