Has anyone else has this problem, with the S/c trucks sometimes running great, pulling hard, then all of a sudden, A DRAMTIC reduction in performace, like the trucks is driving with brakes on. Kinda like the S/c turns off and nothing, almost dangerously low acceleraltion?
Sometimes, turning the iginition off and on resets it, but not always.

Thank You

There's a recall to get the ECU re-programmed on the 02s that may be related.
Under certain conditions, such as full throttle (when the accelerator pedal is fully depressed) in low gear when the engine is not fully warmed up and at cold ambient temperature, the engine malfunction indicator lamp may come on and the engine speed may be severely limited due to programming of the engine control module. If this occurs unexpectedly, it could lead to a crash.
Applies ONLY to 2002 Xterra models equipped with a Supercharger, the following Vehicle Identification Number Ranges:
5N1MD2*T*2C500000 - 541754;
5N1MD2*Y*2C500002 - 541766.
Please be aware that not all VINs within these ranges may be affected by this campaign

Thank you!!

That would be it. Take it to the dealer and have it fixed.