Yea we think its the seals..What he said.
If the catch can was indeed installed correctly, this may be the first sign of worn valve stem oil seals.
How many miles on the engine?
... if I start the car to move it say a couple feet and immediately shut it off and do it a few times (pull it out of the garage to wash it, pull it back in, pull it out again to work on or move something, pull it back in), it'll have a small puff of what looks like oil smoke... YMMV.
FWIW, I've noticed in the past that if I start the car to move it say a couple feet and immediately shut it off and do it a few times (pull it out of the garage to wash it, pull it back in, pull it out again to work on or move something, pull it back in), it'll have a small puff of what looks like oil smoke. If the car fully warmed up during the previous drive, no matter how long it has sat, I do not get that same puff. This would lead me to believe seals are fine.