We have a gurgling, slow to drain toilet downstairs. If it is a clogged vent do we work with the vent on the second story (cape cod style house) or the vent on the first floor over the kitchen? The kitchen is right next to the bathroom downstairs which is right under the bathroom upstairs.

we have a gurgling, slow to drain toilet downstairs. Sure sounds like a blocked vent to me You must first determine which stack vents the toilet and snake from there. Not knowing if you're wet vented or individually vented I can't tell you which stack to snake. Good luck, Tom