My 1990 300zx n/a 2+2 has a problem where after driving it for 20 minutes or so its start to limit the rpms i can reach then bogs down in gear but doesnt stall or die, when pressing the gas further it does absolutely nothing no response. then after im limited to 2000 rpm as if im in limp mode or something but when in neutral you can hit red line no problem only under load in gear it bogs down. so far ive changed
: new oem maf
: new ngk sparks
: new ntk o2 sensores
: checked codes no codes 55 none found
: new fuel filter
: tps
: ptu
checked proper voltage to maf
pls help !!