I had a chance to tear into this a little today and since wetness usually originates from above and collects in variopus places lower down, I started at the top and pulled the plenun off to get a better look at some things (plus I have some other work to do anyway).
It is pretty wet at the front of the engine under the plenum in the vicinity of sensor 11 in the figure below. That sensor is a coolant sensor so it is not the culprit, but I would guess the sensor next to it marked "See 17.07/07a" could be a culprit if it is an oil sensor. Unfortunately, when I go to section 17.07 and section 17.07a in the parts references there is no sensor indicated in that section and only the instrument cluster is shown in that section. Also, in section 17.07 there is reference to an oil pressure transducer, but it also stipulates prior to '98MY (I have a '02).
Can anyone tell me what this part is, what the proper part number for it is so I can order one if it's the culprit, and whether it is a common source of wetness? Are there other common culprits in this general area that i should instead be looking at? It's a little too wet in this area to readily determine a source since everything looks wet (and it all of course collects int he bottom).