Took me 6 hours to find a blocked vent on a 3 inch stack because I kept checking the wrong cleanout
Ran a camera down three times before I popped the cap on the roof and found a bird nest jammed in there. The whole job should have been 45 minutes but I burned most of a day chasing it from the basement up. Anybody else got a go-to order of operations for tracking down a slow drain before you start pulling caps?
Been there man, now I always start at the highest point and work my way down since gravity brings that junk from the top anyway. Pulling the roof cap first woulda saved you five hours.