I know its an old thread, but may be it helps others.
I have the same problem, dont waste your money in anything but the ECU.
Error 25 is not knock, its a fail in the system that detect knock, not knock per se, KS, wiring, or ecm, and, sadly, its always the ecm.
Honda Aquatrax from 2002 to 2007 share the same knock sensor and a very similar ecm, same problem, ecm.
By the way, when you have fi light on and error 25, ecm its in fail safe mode, may be you did not notice, but ecm retards timing at 9000 rpm and drop the power more than 20hp.
Check this out.
http://www.cbrxx.com/general-cbr-xx-discussion/28039-efi-error-25-another.html
http://www.cbrxx.com/general-cbr-xx-discussion/28063-fi-light-error-25-limits-power-proof.html
Hope it helps.
