Oil in air intake tube from pcv breather - GM Enclave Outlook Traverse Acadia

I found oil in my air intake tube from the the throttle body to the MAF sensor. Through some research the reason is that the engine has 2 pcv breather valves that will cause the issue due to the rear one being clogged up.
Click on links for PCV breather valves on Amazon
goo.gl/hoNVDN
goo.gl/PvgC3N
Thanks!