Tim--vacuum crankcase venting helps seal your rings and increases performance. Done via the old drag/roundy round trick with one way check valves connected to the exhaust system is, unfortunately, not permitted by the GCR.

It is probably a safety issue...

Alternatively, if you hook up your air pump from your emissions system to do the same thing, you would be violating ITCS because you would want to force the blow-by sucked out by the pump to a point other than your vehicles intake manifold (oil vapor lowers octane of the incoming air fuel mixture and promotes detonation).