Here is a what the California Emissions Warranty states:
Under the California Emissions Warranty, vehicles certified for sale in California, and those states which have legally adopted California Emissions Standards and Warranty Provisions, have additional coverage beyond that required under Federal law.
Under the California Emissions Warranty, all emissions related parts are covered for 3 years or 50,000 miles, and a vehicle-specific list of more expensive emissions related parts is covered for 7 years or 70,000 miles. In addition, the 8 year or 80,000 mile coverage for the catalytic converter and engine control unit required by Federal law also applies. These California Emissions Warranty provisions cover vehicles up to 14,000 pounds GVWR.
Unless your Ford Econoline Van is heavier than 14,000 lbs the Ford dealer should replace your van's catalytic converter at no charge. We recommend also speaking with the California Air Resources Board regarding this matter as well prior to returning to the Ford dealership.
Note that Federal Emissions Warranty only covers light weight trucks up to 8500 LBS, however California Emissions Warranty covers vehicles up to 14,000 lbs.