[DavesSpectra]

If I were you I would check all electrical plugs in that area for corrosion inside them... Look for a turquoise/blue color "crud" around the metal parts.. That's an indication of a bad connection. If you find any clean/scrape... the crud down to shiny metal. and apply silicon spray/grease to the cleaned area to keep the moisture out.
I have read also about possible activated carbon pieces from the canister getting loose and up into the hose connections causing blockage so the CCV could not release the system pressure.
Dave