All right here goes. I had(have) the same problem for 2 years now. Honda makes the knock sensors very sensitive(down to the most minute amprage) Anyhow, I am guessing, that you (like myself) had bought your ECU seperate for the motor. The sensors that come with the motor, while in the original car, are somewhat "matched" with the ECU. Even the smallest difference in sensors will set of an ECU code. I have been through 3 brand new knock sensors and no luck. You could spend a $G$ trying to match the two. Honda makes 12 that i know of just for the b16A. Your best bet is to have your ECU chipped. I know this sound "jerry rigged", but it won't read the knock sensor and you can manipulate your fuel/timing curve/vtec point? rev limit etc... hope this helps with your quest. Good Luck
matt