With a 3 inch lift will I rub with 285/70r17 on a 17x9 wheel? 2017 trd sport 4x4

Curious if I'm gonna have to trim.

 

Most likely yes. I don't have a 3rd gen, but ran the same set up on my 2nd gen (285/70-17 and 17"x9" wheels -12mm offset) and needed to trim.

You'll need to trim the black plastic inner fender liner in the front and rear of the wheel well. Doubtful you'll need to trim the actual fender, most likely just the inner fender liner. If you do need to trim the fender it should only be the very rear bottom of the front fenders which would also yield a benefit to do the CMC.