9 times out of 10, you won't know the knock sensors are working.
they're nearly invisible unless you really know what you're looking for!
UPDATE: Will, i just got done with the custom KS rewire harness with single input, dual output, soldered/sealed up the temp gauge wire on the T-stat housing, and re-wired the o2 sensor (the broken wire). i de-pinned the connector, and soldered a new wire on for ya.
the CEL is no longer illuminated, and the only code present is for the HAC sensor.
(which your wires are cut off, and you don't have the sensor- but it won't affect you unless you drive up in the mountains)
the car drives really nice! i hit about 5psi quickly just to make sure all was well, and it pulls nice and strong.
*don't boost on that fuel pump though! you're asking for disaster if you do!*
i have about an hour left to work on it- i might wire up your SAFC if i get a chance.
so, the car is pretty much done.
oh yeah, you need to go to toyota and get the copper crush washers for your powersteering pump. all your fluid leaked out on my driveway. now it's all stained.
here's the P/N for it: 44327-12010
44327A in this diagram-
http://www.cygnusx1.net/Supra/Library/EPC/291410/catalog.aspx?F=4503&P=1
-shaeff