Today me and a friend hook up his scan tool to my car cause it's running like crap and I got 2 codes that showed up one is P0300 which is random miss firing and i'm pretty sure it's either the coils or the wires. The other code that shows up is P0748 " Pressure Control Solenoid Electrical" ??? Anyone know of this code and what is it and how would I go about fixing it.???

I got the same code and gm says it could be my B&M Shiftkit wires on my tranny, check your tranny wiring harness make sure everything looks normal on it.