My buddies 01 trans am has a sts kit on it with only 5 lbs and he has a breather where the oil cap goes and at idle it is smoking out of the breather and has a faint smell of exhaust and under boost it blows oil out of the breather and gets on the headers and so on. But this smoking out of the breather is this most likely blow by or could this possibly be from the PCV valve that could possibly need replaced. Thanks