im kinda confused on what your saying man, maybe some more detail?
like was the car running fine, you installed just the sensors an did nothing to the tune at all, Then it just started acting weird?
or did u try running on a speed density tune?
id recommend going back to the last tune that worked, if that dont work unplug the breakout box so its not connected to the ecu an try starting the car again..
btw, is nismotronic even connecting an stuff?