[96riviera18]

vac leak? chedck all the vacume hoses for leakes and cracks.
p0300 is random misfire code which is caused by the cam sensor not reading right (p0341). the EVAP code, TCC, and system lean codes may all be different problems.
do the rpms climb when you try to accelerate and the car just doent move? (ie the converter isnt locking up and your in neutral?)
in my experience, the superchargers rarely go bad and there is almost no way for a roots blower to not work at low rpm and spin at high throttle levels since it is run by the belt and spins along with the crank pulley. but you should replace the coulpler in the snout if you really want to rule out the s/c, and check the bearing. (pull off the belt and see if the pulley has any play)