+1 with what Jstreet said. Also, on the Diablo to turn off the rear O2s you go to Modify Parameters--->OBDII--->
This is from Diablosport:
To set OBD-II setting for no rear O2s - turn all of the parameters to the "OFF" position: OBD-II MIL / OBD-II Test Heater bank 1 downstream / Heater...