2004 Buick Regal GS 3.8 sputters and dies NEED HELPPPP

Car runs, but when driving tries to die out. Sputters badly
and dies. Seems to have started having issues when I put
my radio system into it, but not positive, could just be
coincidence. Replaced fuel pump, was ok and a week later
the same issues started up again. (It was a cheap pump,
but dont know if that matters) Scanned the car with Modis,
several misfires came up, so I replaced ignition control
module, and all 3 coil packs. That didnt fix the whole issue.
I checked the fuel pressure with shroader valve, wasnt any.
I was told to try a new fuel pump relay - ran better but still
sputters and dies. Now going to try a new fuel filter (which I
doubt will solve the problem) I have been trying to fix this
car for MONTHS, now that I'm moving I desperately need it
running. Any help is greatly appreciated,  thanks!!!!!