A rewire is a commonly needed thing with the knock sensors.... although you need to use shielded wire. I'd rewire those and use some RG-58 coax cable. This replaces the old wiring and adds a grounded shield to help reduce interference.
Writeup and detailed info:
http://oldschool.supracentral.com/htm/knock.htm
Be very careful when working around the knock sensors, Toyota wants a LOT for new ones.