[95blkmax]

on PWG N20s it's not an easy diag. A few things can cause that code. I will focus solely on this vacuum oil situation as it is a known issue being presented...

How are the vac lines from the pump to the engine cover/ reservoir, and from there to the solenoid? Oil could be present at normal amounts, but if the lines are dri-rotted they could collapse under vacuum and cause this code. Oil in the reservoir isn't uncommon at all. Just how much oil are we talking about though? a drip of oil is normal. A pouring stream is likely a failed/ failing vac pump.

Note that if it is in fact a pouring amount of oil, if that oil made its way to the solenoid, it is POSSIBLE to clean it out and it work just fine after. Certainly worth a shot at that point (spray brake parts cleaner into it and let it drip out til clean, then a light quick spray of WD40 to prevent rusting inside). If upon replacing pump, cleaning out lines and solenoid, the code is still present, you'd want to replace that solenoid next (or honestly, if it's the original solenoid... just replace it along with the pump and be done with it).