Are you blocked by trees? (My wife & I recently looked at a couple of houses for sale in your area, so I think I know the answer.)
Reading the
manual for the H2160MW9, it looks as if the tuner is not one that allows manual addition of digital channels, just manual deletion (what a great feature
).
I suggest that you hold off trying to block real channel 13 reception. You need to focus on receiving a reliable real CH-38 and in so doing, you may find that the signal on real CH-22 is made reliable also. (If you are happy with the quality of virtual channel 22.2 (broadcast on real CH-25), that takes care of KCPQ reception... but the signal on VC 22.2 is about half the bit rate of VC 13.1 on real CH-13 & 22. (Yes, virtual channels and real channels can be confusing
).
I still think you need more antenna than a CS2 to make the KOMO (real CH-38) reliable. As I mentioned earlier, "Antennas such as the Antennas Direct 91XG or Winegard HD9095P are appropriate for going after the Queen Anne Hill group (KOMO, KING, KONG, KIRO)...". As you have seen, altitude is also your friend.