"Mais peut-être vais-je dans la mauvaise direction ?"
my question never had to do with the translation of "direction." (although i would say "way" when speaking normally, "you go this way, and if you see this landmark, then you've gone the wrong way. but then turn the other way and you'll be going the right way... etc" compare with "you go in this direction, and if you see this landmark, then you've gone in the wrong direction. but then turn towards the other direction and you'll be going in the right direction.")
it had to do with the fact that duolingo required "in" before the word "way." "in" is required with direction "you're going in the wrong direction" although "you're going the wrong direction" also works. but when "way" is used, "in" is awkward: "you're going in the wrong way" vs. "you're going the wrong way."
that's all i was saying: that if one translates "direction" as "way" which is completely acceptable and used more than direction in this sense, then the "in" become superfluous...