my 1994 sc 400 has a51,52 code which means bad knock sensors, i relaced them!

What is your question?

i replaced both knock sensors and that did nothing to help the problem,i lost $400.00,plus labor,i had the computer re done,for $300.00, that didn't help either'i had the wiring traced and tested,they were fine,car still reads code 51 and 52,bad knock sensors,no power, it ideals up and down, can some one tell me what the problem is?