i just went to radio shack and bought a roll of shielded wire
only shielded wire they had available at the time was something like this
http://www.sesystems.com/West-Penn-...=google&utm_medium=Base&utm_campaign=Products
instead of having 1 wire that is shielded i have 2 wires and then the shield
so what i did was use both wires for 1 knock sensor
then did the back knock sensor with another length of wire
grounded my shielded wires on to a (fresh metal)clean ground on drivers side strut tower
did this about 6 months ago(7,000 miles)
still holding up great with no code 52
my back knock sensor plug was busted...so i just used a femal spade connector
but last night i put on a new connector
never had problems from the spade connector though