ended up being a 1/4 inch hex bit for those bolts.
and i'm confident in saying...if i didn't have my clutch fan removed already, this project would be a real b*tch. the position i found that i could work from was standing on top of the front sway bar in like a half-fetal position with my left hand around the back of the passenger side exhaust manifold and right hand down the back of the motor just to the drivers side of the trans stick tube.
1/4" hex bit, several different length extensions, and a swivel joint all on a 3/8 drive ratchet is what needed for tools.
p.s. i didn't exactly "replace" the sensor, i slotted the mounting bracket holesabout 3/8" and reinstalled. so far the butt-dyno definitely approves of this mod[sm=yeahsmile.gif]we'll see how mileage is affected
(a quick camera phone vid, looks like 0-60 is between 8 and 9 seconds, actually maybe even a little quicker since my speedo hasn't been calibrated for the 285/75/16's, with a little tirespin thrown in there wheni went overa bump)