Generic Consult? Never heard of such a thing for post 95/96 vehicles. She will need an OBDII scanner. Nissan ditched the Consult protocol to maintain vehicle EFI troubleshooting standards in the mid 90s.
There’s an OBDII scanner for sale at Crappy Tire for $179.99. Wally-Mart one is probably a little cheaper.
As for your rumble while driving. Funny you say that. I was just reading on a 300ZX board that the same thing happened to him. He took it into Nissan and they told him one of the Injectors had died. It is not so common on the Pintle-less 350Z injector style but entirely possible. You may need more diagnostic than an OBDII port… unless the OBDII tester can do a Cylinder Balance Test, or you are willing to get under the hood and pull injector connectors one by one.
PS… When my car rumbled like that, an injector went out of spec. The last time was in Rabbits video at a CG underground meet a couple months back… Useless information