I thought they did, But seeing the FCP site below -It's because of the manual transmission.
I wasn't saying that that's your trouble for sure -it just pops off sometimes. And it had popped off on mine.

my '97 NA has it and it was too hard to get to, so the indy did the repair
The hoses and elbows of the PCV, on both sides separate very easily on my car, and have been a little bit trouble.

Here are the different set ups
http://images.google.com/imgres?imgurl=http://www.fcpgroton.com/images/products/thumb/pcv9596_850T.jpg&imgrefurl=http://www.fcpgroton.com/category-exec/category_id/63/nm/Breather_System_PCV_/&usg=__PPNobp3xUWbHtJRnULS0O4-Skwk=&h=100&w=79&sz=4&hl=en&start=15&sig2=sOxTOa8mSJNG4dmekXgHuQ&tbnid=pPrHpvvTkygKpM:&tbnh=82&tbnw=65&ei=3t-YScyRItqhtwe4gq2lCw&prev=/images%3Fq%3DVolvo%2B850%2BPCV%2Bsystem%26gbv%3D2%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG

Here is a manifold removed -full PVC replacement
http://lakesidedp.com/uploadpics/pcv/
in the bottom picture, just to the left of the bottom arrow head.

and this: http://volvospeed.com/Repair/knock_sensor.pdf on page 19

This thread is 3 pages long and has a lot of info if you can get through it:
http://volvospeed.com/vs_forum/index.php?showtopic=80459&st=0

same on turbo and NA ?
It depends on the tranny

--
'97 855na, Mobil 1, K&N, various IPD's and eBay's