code 2141 knock 'regulator?'

[Livolsi, Stephane]

Anyone with knowledge/experience in this, I would appreciate your input.

Patient is a 5KTQ.  rotor/cap/wires are recent, plugs are confirmed good
shape (visually)  Recently fixed air temp sensor and have given the car
a really good look over for vac leaks and replaced some suspect hoses.

Today, under very light boost in 3rd gear I got the check engine light
and dumped the codes and got the 2141 which I looked up to be the knock
regulator.  Did not notice any loss of power.  I tried to get reproduce
the situation (3rd gear, accelerating up a hill) that gave the warning
in the first place but could not get it again.  I always, always only
use Chevron Super Supreme 94 octane.  SJM site says fuel octane too low,
excessive compression, excessive boost as causes.  I listened to the
engine and did not hear anything out of the 'ordinary'.

Any ideas what might cause this code?  Are there any usual suspects? It
is the first time since owning the car that I have got this code (2.5
years)

TIA

Stephane