the part you circled is the AOS (Porsche's version of a glorified PCV). It's a known weakness in the system which can, in rare instances, cause catastrophic failure. You can step down from the ledge though
as yours just looks dirty and any oil could have simply just gathered there.
Pull the tube off where it connects to the throttle body and see if there is any oil pooling in there. If so, yours could be on it's way out. Since you have the CPO, you may want the dealer to inspect it on your next visit and see if it needs replaced or you can DIY for ~ $120 (though I did see Sunset had them advertised at $87 in a recent P magazine) and about 2 hrs time.
Lots of details here if you do a search on AOS
