i have a built 1989 4Runner 22RE that has been giving me hell the engine runs GREAT, but if i rev it up to 2000 rpms i get a code 52, which we all know is knock sensor circuit code. I have done all the "normal" fixes but last night i started it and reved it to 3000 rpms and held it there for three mins. and never got a code 52 but as soon as the rpms dropped to 2000 the light came back on WTF HELP ME PLEASE!!!!!!!!!

engine is a bored .40 over 22RE with a pro comp racing head, and comp cams, and header