Obd2 port

Could you not just use the obd2 port to gain access to the can network?

depends on the vehicle wiring. many cars have multiple CAN busses, and the one you may want might not be connected to the OBD2 port. Best to study the factory wiring diagrams found in the service manual to be sure.

it's dependent on the platform. various makes and models use a CAN Gateway, isolating and restricting what information is supplied on the OBD2 CAN Network.