Knock sensor bank 1 low input

[/Luke/]

Hi all

My engine light keeps coming on,the DTC is P0327

I have just replaced both knock sensors with new ones, the car has been driving great but the engine light come on again with the same DTC as before I changed the sensor. What could be the problem now?
It a commodore 2007 VE Omega 3.6 alloytech v6

thanks for the advice in advance