Torque to yeild bolts should not be reused, at least the Ford torque to yield bolts are not reusable. When they are torqued to yield, they are streched and are no longer usable.
On the Ford system, the bolts are streched beyond use. After torquing to spec, they are turned an additional something like 1/4 turn (the "torque to yield"). Torque to yield is common on engines with iron blocks and aluminum heads.
You best be checking a Toyota shop manual before you go any further.
On non torque to yeild bolts, the threads are to be clean and dry (or at the most, very lightly oiled). The torque sequence pattern in the manual needs to be followed (usually starting from the middle and moving outward). Do not back off when moving to the next torque setting.
