I changed the secondary canister filter late last fall. I just bought all new filters, air, both fuel filters, oil, and I have had planned to change all when I come up to 5k, another 1000 miles or so. I thought also that I'd wait and let the old fuel filter in there now pick up anything the B-20 has loosened up from the tank, lines, etc, before putting the new filter in.

On another note, I did notice a slight drop before the B-20, but had to do with dragging a left front brake pad with a seizing caliper, but that has been fixed.