That's the first thing I did when I took delivery of my car...checked all the "tune-up" parts. I found that I had all the OEM stuff still in the car after 15 yrs!!!
So I went to the chevy store & bought all new stuff. The OE PCV's did just what you described. I thought it was rather neglectful for the orig. owner to leave all that stuff in there that long!
I figure that changing out the A/Filter, PCV's, F/filter every yr. should be standard maint.?? Okay the OE plugs were still good but 15 yrs! Maybe I'm wrong but wtf if you keep up with the small stuff I figure it goes along way to enhancing less trouble from the small things.
My PCV's had small hose clamps on them & I thought it might have been that way from the factory, since nothing was touched!?
Did you get a scan on the car??
Tom