I was a econ major too. And yes a 157 is bad enough to possibly knock me out of T14 even as a URM
You should be fine for Penn if you can pull off a 167 and write a decent "Why Penn" essay. You might want to include an addendum about the GPA, since LSDAS shows it in relation to all Emory students, not just those in the B-school. If you get above a 165, I would cross Temple and Emory off your list. With a 3.1, H, S, and especially Y will be a stretch, but stranger things have happened.