Markellos, I'm using the 845 catless DP with OEM sensors and no problem (touch wood).
When I replaced my OEM ECU with the spare, I immediately threw P0447 - Evaporative Emission System-Vent Control Circuit Open; and P0453 - Evaporative Emission System-Pressure Sensor High Input. These occur in Australia because we don't have these sensors on our vehicle.
I haven't popped the P0462 FUEL LEVEL SENSOR LOW VOLTAGE. Look
here for further information. May help??
P0447 and P0453 can't be cleared (tried at my dealership after the spare ECU was VIN matched and installed by them) but I don't know about P0462.
If you get your spare ECU tuned , your tuner might be able to permanently delete these DTCs.