Here is the complete scan/diagnostic:  
  
P0303  misfire #3 cyl -- change plugs n wires? 
P0325  knock sensor #1 malfunction -- where is the sensor?   
P0420  Catalyst efficiency low, bank 1 --  what is this? 
Failed fuel flow -- changed filter 
Plug wire #3 cyl short to ground --  waiting on parts 
Plugs 1&3 breaking under load --  changed plugs 
Bad knock sensor 
  
Can anyone tell me where the knock sensor is and is there any advice in installation?  I managed to break off the bolts from the washer fluid tank to the strut housing - minor glitch but would hate to do similar to the sensor  
thanks 
97 legacy L, 2.2 AWD, auto trans