Mazda genuine factory valve cover gasket or third party one?

[quigley2003]

I was changing my spark plug and there was oil on spark plug three and four It looks like our valve cover gasket is leaking my question is should we use oem Mazda genuine factory valve cover gasket or third party gasket.

 

[Lazy2.5]

It could also be from overfilled oil or excess pressure in the crankcase.

 

[erhayes]

Make sure the PVC is clear.