If you are looking at a GPU upgrade in the vicinity of a GTX 1050 Ti or so, your i3-4160 may suffice.
If you are looking at a more powerful GPU in the likes of a GTX 1070 or above, you should upgrade your CPU to at least an i7-4790 (or i7-4790K if you want to/if your mobo can OC).
If you are looking at a GPU upgrade in the vicinity of a GTX 1050 Ti or so, your i3-4160 may suffice.
If you are looking at a more powerful GPU in the likes of a GTX 1070 or above, you should upgrade your CPU to at least an i7-4790 (or i7-4790K if you want to/if your mobo can OC).