2005 PT cruiser Turbo (wagon) freezing, sputtering when accelerating...PCM code?

Hello! I have a 2005 PT GT Turbo cruiser (wagon). The car will start
and as I'm driving and try to accelerate the car will not allow me to
do that...like it is freezing up and sputtering. So I take my foot off the
accelerator..and it coasts slowly..I then step on the gas really fast
and it seems to kick it to run fine again sometimes for only a few
minutes sometimes for a longer length of time. But this happens at
strange, random times and it is happening more now after I replaced
the parts below. It will be running just fine..then I can't accelerate. I
replaced the cam sensor, crankshaft sensor and o2 sensors, plus
new battery and battery cables. And went to Oil stop got the new oil
filter, oil change etc. It still happens. Diagnostic comes up as a PCM
code. A mechanic says I need to get a pre-programmed computer for
this and it will fix it. Can a messed up PCM really cause this??
Someone else said maybe it could be vacuum lines, fuel pump or
fuel filter...or the fuel things(?) need to be blown out (for years I was
using cheap, plus gas instead of good premium gas I was supposed
to use). Also, I put in high octaine booster and later a fuel cleaner.
Nothing seems to work! Is the PCM code realistic and should it be
trusted? Thank you for ANY help and time!! I have a lot of long
distance driving I need to do for work next month I can't have this car
doing this.