From what I gather, the answer is Maybe. It might be up to the overall condition of your car.
I have heard a few accounts of people getting their 5wire fed VXs to pass smog. However, I was not able to. See my post here:
http://www.gassavers.org/showthread.php?t=12488
You should not hesitate on a VX purchase. CA or Fed, they're great in both configurations.
I think you should try to smog it in Fed (5-wire) mode with the contingency of changing (temporarily) to a CA ecu if you are not successful.
You can come by a CA ecu on ebay for ~$100. To swap it out, pull up the carpet on your passenger side, unbolt and unplug that little gold/silver box and swap it out for your new ecu. No skills necessary, just a little determination.
Please let me/us know how it goes.