I've got it in my head that for a VY the GM oil pressure PID does not work. For EFILive the oil pressure is a calculation that uses the oil pressure sensor voltage. I've had a bit of a search online and can't find the info however I believe the reason why the gauge in Torque doesn't work is that the ecm doesn't ever convert the voltage to a pressure reading. I don't have my dongle (brother in law has it) so I can't even go out and check.
Just found this now from earlier in this thread from Swingtan
"The data for specific PID's is dependent directly on the OS inside the PCM/ECM and requires specific code to get the data. This is not always supported and in cases like the "ODBII Scan Gauge" used by a few here, may not work ever. It's known that custom tunes performed by the HPT suite caused a few of these gauges to stop reporting certain PID data."