An update:
Service engine soon light came on while driving yesterday. Car's making a clicking noise when coasting. Might be the CVT going? Will find out sometime as it's at the dealer's again. 
This happened to my car (2003 Spec-V). The cause was a misfiring coil pack The low RPMs and check engine light means that the car was going into emergency mode. In your case it could be a number of different things.
Any update on what happened?
Honestly, I think most Spec-Vs are lemons. Nissan's QR25DE engine has been a major headache for numerous drivers...