I just recently bought a 2000 camaro z28 from a dealer about a month ago.
I just recently noticed a faint white smoke coming from the engine. It only apperars after the camaro has ran for a about 5 minutes or so. It does not have any smell and is pretty unnoticeable but smoke comes from the area on the top closest to the windshield.
Another thing that my be related is the service engine light comes on and goes off randomly. I got it checked and the code was a catalytic efficiency. I got the cats checked and they were just fine.
If i can get some help as to what that source of the smoke may be that would be really helpful.

 

i would check for exhaust leaks. can you hear a "tick tick tick" anywhere on the engine?

 

Could also be oil leaking from somewhere such as a valve cover gasket, dripping on the exhaust manifold, and burning.
Oil burning on the exhaust will appear more like a white "steam" color, not a black billowing smoke.

 

it could be one of the cats gaskets need to be replaced

 

should I be concerned about this? Like the smoke, is it a big deal or can it wait like a few weeks?