Do you know anything about the O2 simulator and Virginia emissions testing?
I believe here that they do not actually test at the exhaust, but they connect to the ECU and read the O2 from there as they run the test. If it passes, then you are 'ok'. They do this for all vehicles newer than some year (not sure which year it was).
So I think it's a matter of whether or not the O2 simulator is detected. Is that thing obvious when you look at the engine bay? For that matter, does it read like something that would look reasonable, or do you get 'unrealistic' O2 readings? Would the mechanic notice?
edit : This is rather unfortunate... because I'm sure the car would pass easily if they just tested at the exhaust pipe... Every time I test my old honda my readings at the pipe are under 10% of the limit. The 335 would pass *easily* with primary cat delete.