Random knock at cruising speeds

[Kevin 1G Drummer]

This seems to be a completely random thing, but every now and then my car will start knocking and pulling timing under light load/highway speed cruising. I have my DSMlink setup so that the check engine light comes on for anything over 3 counts of knock, but I don't have a laptop so I can't log it when it's happening but I can feel that it pulls timing. As soon as I completely let off the throttle and decel starts it goes away. After that, sometimes it stops, and sometimes it comes back right away so I have to let off the throttle again. Sometimes it's fine for a few seconds/minutes, then it comes back again.

I was thinking it could possibly be a faulty knock sensor, but I don't really have any idea.