Hi,
As far as the sensors being "delicate" to the touch...Uh...not so( as long as they are the "shielded" type. I actually have removed all four sensors from my SVT and have "torched" them watching for switching speed. I couldn't tell much from the experiment (they did switch), but I will say that I did notice a difference, although very shortlived, after re-installation. My idle was much improved for a day or so.
Don't worry about "touching/handling" them as you would a new spark plug. The torching did burn off some soot and slightly improved the color of the sensor as viewed through the little holes, but I do not think it will cure/revive a sluggish responding sensor.
I tried every way possible with tools on hand and could not remove the rear bank, pre-cat (OS11 I think)sensor...untill went to NAPA and bought a $12 O2 sensor socket. Made all the difference in the world for that one sensor. The others were no problem with ordinary 7/8" (22mm) hand tools.
...Ed
