1988 Wrangler 4.2/BBD ---Can anyone comment upon changing the filter on the charcoal evap. cannister which is mounted under the coolant and washer fluid containers ? My Jeep has 120,000 miles and I am trying to revitalize as much as I can . Is there a simple access route ? Part number to replace ? Can the filter be cleaned and re-used ? How is the cannister opened to get to the filter ?