If you jump the high pressure switch plug on the accumalater, the high pressure switch is unplugged, therefore the compressor won't be cut off by the high pressure switch. R134A is still considered to be a freon, and don't waste money on an evacuation machine unless you really want to save the freon, it does harm the enviroment, but so does running your truck, chemical plants, and many many other things, so no its not a very responsible thing to do, but it wouldn't be the end of the world, its not like your releasing freon on a daily basis. But as someone posted before, DO NOT LET IT SRRAY YOU IN THE FACE, best thing to do is borrow or invest in some AC gauges. And if I'm not mistaken, isn't the orfice tube located in the condenser on the 98's?