A State Police K9 on duty in Danbury yesterday found marijuana in a car pulled over because of an expired registration.  A Trooper was using a license plate reader and got a hit on a passing vehicle on I-84 westbound by exit 6.  The driver was pulled over and found to be operating under suspension.  A small amount of marijuana was initially found by the Trooper. The vehicle was then searched by K9 Favor, who turned up 13.5 ounces of pot, along with various THC vape cartridges.  The driver was taken to Troop A in Southbury.  Police did not immediately release the person's name.