I also live in Montgomery County.
As long as you aren't pushing a CEL for anything emissions related, and visually still have Catalytic Converters (basically it can't LOOK like you've removed anything that is emissions related), even if you did remove it, it can't look like it.
They just hook your car's OBD2 port up to their computer and make sure all of the sensors are reporting the correct ready reading. Done and done. We aren't hooked up to sniffer's or anything around here.
Due to extensive Mods, my Monte Carlo would never pass, so I keep it under 5000 a year and get the exemption haha. But I did use HPTuners on my car when it did need the inspection to turn off the CELs and never report them.