same codes each time

i keep getting the same 3 codes each time and before I replace each item just want to clarify that I need to.

I get 16804, 16523 and 16795. I clear them and they all come back in around 200miles.
the sai code was there before I removed all the mess aswell so not related but could that code cause any running issues as its just the sai?

I understand the cat efficiency and slow response from the sensor could, but could it be the cat and sensor or one or the other?

thanks very much guys