Hi all, there is many videos about oil catch can, any body have useful information about it? is it already available on mk4? Or did any one already installed it ?

Hi @Bima, as far as I am aware, there are no plug and play catch cans yet. APR list their GEN 3 MQB compatible with the DNPA GEN 4 engine, but there are not, or at least I haven't been capable to find, feedback from people who installed one. 

For me, best objective feedback I've found so far is Charles' outcome after he installed one on his 2019 Golf:

 

 

For me, it's not worth its price; however, what I do in a regular basis is adding Liquy Moly fuel injector cleaner (1971) to clean and prevent carbon deposits. 

Engines have sophisticated built-in oil separators for the last couple of decades.