I had a new PVC kit installed and a new oil cap gasket installed. But from that hole the oil came out anyway. I believe that the oil leaked from that hole for a bad valve cover replacement by the mechanic, who then resolved with that nut shown in the photo.
The secondary air injection system in which international markets was expected?
I post a picture of secondary air injection system (picture taken from internet):
This system is good to reach quick optimal temperature of work in cold climate?