Hey mate - Might get a better repsonce in the forced induction section!
What knock levels have you been recording mate and what sort of driving was it?
My car is just a 33gtst and normally on the road the highest I have had was around 60 because of bad fuel and a hot day. Normally see around 20 when I bring her out?
At the track though.....different story!
The knock sensor does and can pick up other noises which results in a high reading.
I did a supersprint at Bathurst and on my high boost tune/setting got 88 knock...but that was going 9/10th's (ripple strips, going quite hard so good chance it picked up other noises and stuff)
One point to remember is the frequency.
How often do you get the high knock reading?
Is it everytime you drive it?
Do you know what the tuner has set the knock warning at?
(Mine is at 60 and the engine light flashes)
Hope the helps mate,
Cheers!
Chris