PCM DUMPING TUNE ???

OK AS U GUYS KNOW I HAVE HAD ALOT OF TROUBLE WITH MY CAR THE LAST FEW WEEKS FINALL MY TUNER HAD IT ALL DAY SUNDAY AND IT RAN GREAT UNTIL YESTERDAY IT STARTED MISSING AND RUNNING LIKE CRAP I PULLED A PLUG AND IT WAS WHITE SO IM GUESSING ITS RUNNING LEAN BUT I KNOW HE HAD THE AIR FUEL DIALED IN CAUSE HE SHOWED ME AND ITS THROWING P0602 SO I CALLED MY TUNER AND HE THINKS THE PCM IS DYING AND ITS DUMPING THE TUNE I ALSO CALLED SCT THIS MORNING AND THEY SAID THAT COULD HAPPEN .... SO HAVE U GUYS EVER SEEN THIS HAPPEN BEFORE ????

THANKS
RICHARD

thanks ... how do i do that because i really want to make sure its bad before i spend 400 bucks but at the same time i dont wanna mess up my car its my daily driver

so my tuner calls me and asked me if i knew if the ppl who put my cams in degreed them and used new cam bolts so i call them and they tell me no we didnt degree them and the cam bolts are resuable ..... im like are u kidding me .... could this be my issue this whole time ????