GS-type-R

I am getting a dtc p0450. you should know that i have a 96 gsr with a 2000 type r swap. I have done everything necessary to make this swap legit and it was for a while...however now i am getting this code. Can anyone help me diagnos this DTC. The dealer says that this code doesnt exist for my car...but this is the code that the reader gives me. It has something to do with the evap system i think, however there may be other causes that are throwing this code...i dont know.
Any help is appreciated.

Thanks,
GS-type-R

Relic1

a little background on your swap is needed.
which ECU are you running?
are you running the OBD2b ECU with a conversion harness?

for the record... P0450 EVAP Emission Control System Pressure Switch Malfunction