ES9J4S oil disappearing

[2xV6]

Hi all.The story of this topic is quite a big oil leak from my daily 406 brake v6 (es9j4s).Bought this car as my daily ,so it was a cheap,really cheap and the problem is that engine might burn or leak oil,the amount is about 300ml after 250km.Engine runs fine,starts easily makes quite a lot smoke ,which is white,smokes more after you push throttle ,but when idling ,the amount of smokes decrease,but it also has anti-polluton fault ,cause previous owner decated before second lambda sensors.All engine is covered under the oil ,all for 4 covers leaks which is massive and oil drops always hanging out at the bottom.Also this one is lpg converted.Before buying another engine (they are cheap here) I want to check everything,so any ideas guys?

ps. tomorrow gonna check those oil breathing pipes.