Well I'm no mechanic but just thought I'd share because for months now I've been trying to figure out why my 2018 T2 1100cc was surging like air was getting in somewhere.. and it was!! On the back side of the intake below the air filter (its metal) and again sorry for the ignorance, but their are two vacuum ports, inside has a hose attached to it and the one closer to me had nothing on it and when I put my finger over it and had my husband start it, the surge was GONE! maybe I'm getting excited over something simple but we never noticed it before. Hope it helps for someone with the same problem.
