The next step would be ..... drive your car for a while and then watch for it.
P.S. .... Have some fun driving it

 

You say no driving for winter. Im guessing its just cold. I bought my car in the summer and have not drove it again till now. I had what I thought was a lot of smoke coming from the exhaust but looking closer you can see it evporate. It just happens when its cold when you first start it up.

 

If your cat is broken loose inside etc it will send volumes of white smoke out the back. It looks like steam. If your car sat for awhile, that's usually when it occurs. Another indication is dripping from the exhaust, usually black sooty stuff.

If you don't see a water leak plugs looks good and your engine seems to run fine, check the cat. I'll bet your 02 sensor is gone too if that's what it is. Do you hear a rattle at all?

If you think it's your cat, it's covered under warranty till I think 80000 miles regardless of who owns the car.

fltsfshr

 

Have same problem. Didnt drive the car for winter and I washed it once during winter. Guess whater got insed and now burning out. I could tell it was steam and I had some water coming out my exhaust. Hope nothing damaged.

 

Actually, I do hear a bit of a rattle. I am replacing the exhaust come spring, so I will check the cat and O2 sensor then. Thanks!