1994 850 turbo wagon 60K miles.

Can hesitation cause a knock sensor CEL? or viceversa?. Here are the details:
Recently my car started to run a little rough...more like hesitation.Right after I feel the hesitation the CEL comes on and it is the 1-4-3 (knock sensor). I have cleared the code, but it will show up again as soon as I feel the hesitation...sometimes within 3 miles....sometimes 10 miles.
Hesitation doesn't happen all the time.
It is worse at low speed, as the car starts to move from stop.
If I floor it, there is a little hesitation but as the turbo kicks in it pull clean and very strong (hasn't loss any power)...almost like you clear your throat.
I thought about fuel filter or fuel pump (never changed), but it feels very powerfull and clean at full throtle, so I kind of ruled out these two.
I haven't seen any correlation with humid, hot, cold weather or cold or warm car.
I always use best gas available (93).
The spark plugs and air filter have about 7K miles.
When it hesitates, it almost feels like missfiring, but I don't have missfiring codes, only code is knock sensor.

I don't want to take it to the dealer because sometimes it doesn't do it, so I guess the dealer might not see or start replacing parts ramdomly.

Any ideas as to where to start would be appreciated.
Thanks.