TURBO or NOT?
An issue like this is usually a boost issue. If you have no leaks in tubing after
the turbo, then it's usually and over-boost condition, and power has to be
reduced to save the motor. Over-boost can be caused by a failing diverter
or blow-off valve. This isn't a condition fixed by plugs, coil packs, and
in most cases not even an 02 Sensor...
If it is not a turbo, then it changes the entire reasoning...