Not sure how strict it is there but where I live we have emissions testing and I was able to pass the sniffer with a full exhaust setup. (2.5in -> SZ Downpipes, SZ full testpipes, and B&B catback with no cats) One or two of the readings got close but not so close that I would be afraid of going back and having it retested. I do however agree that the best bet would be to find a set of stock cat pipes and bolt them in for the test. As long as the car isn't cold when they start the test it should be alright even w/o the precats on the stock downpipes.
