2002 Trailblazer

Any Ideas? I have a 02 Trailblazer that on Monday it gave me a code of P0300 (Random misfire), then two days later P0301 (Number one misfire); (I replaced plugs, boots and cam sensor) ran fine for 1 day now its a P0758 code (Shift solenoid B Electrical)

So does it still run fine and it has this code? Or does it run bad and the transmission’s not shifting? Is the misfire gone? P0758 has to do with 2-3 shift solenoid. Or I should say the 2-3 shift solenoid circuit is electrically challenged. Could be anything from wiring, to ignition switch, PCM, shift solenoid, loose connector, transmission. Of course the first thing I would try is unplugging and plugging back in connectors at trans and PCM, clear codes and see what happens.