The phrase "had him off at the pass with Ecto 2" likely comes from a scene in "The Real Ghostbusters" cartoon series, where one of the characters is describing a situation where they intercepted or thwarted someone or something using a vehicle called "Ecto 2."
"Ecto 2" is a reference to a vehicle associated with the Ghostbusters, typically used for transportation or in their ghostbusting activities. In this context, "had him off at the pass" suggests that they intercepted or stopped someone or something before it could progress further, possibly using Ecto 2 to do so.
Without the specific context of the scene, it's a bit difficult to provide a more precise interpretation, but the phrase seems to describe a successful intervention or interception using the Ghostbusters' equipment.