you will need someone local to answer that, i know pa law not maryland.
in pa
newer cars only get obd2 testing, so if you have programming that by passes the secondary 02 sensor, so the light won't come on. you will pass the actual test. if they don't offer a chip tune. then you can fabricate a mil eliminator. to keep the cel off. most people put in dummy cats (or hollow out their stock ones) to pass the visual part of our test. (as long as it was not done by our shop, to hollow out a cat for someone is illegal)
for sniffer tests you need to be tuned well, depending on hat the states perimeters are for your car it should be able to pass without a cat. If it doesn't then you can retest. and some shops around here who still have their old sniffer equipment (the ones not hook directly to the states computer) will do a pretest and tune to get you into the range. other people i have heard of running denatured alcohol at a 10:1 ratio the tank before your test will make you pass. but i don't recommend it.
most of the cars we did aren't driven in winter. so they all qualify for the >5000 mile exemption. plus i think it is up to pre 84 now only needs to pass a gas cap test.. (that part keeps changing) and we didn't typically see a lot of typical people come back for maintenance. only the high end cars would come back for that.