^^That.
I'm saying these things...
1) You have Flow IN mods, where are the flow OUT ones?
2) The octane comment was to say since you're running 87, go run a higher octane and if the KR levels go down then it probably isn't false since a higher burning fuel is killing the KR.
3) Check the motor mount/trans mount...if they are toast and the engine is allowed to move enough, the downpipe could be making contact with the sway bar causing false knock. Easy way to get around this is flipping it upside down, getting solid rubber replacement mounts, flipping the upper dog bone mounts or getting polys...also...getting an aftermarket DP, or headers...would get rid of that knock most likely too.
