If they do OBD then there is no additional tail pipe test. The OBD willl report on the emissions directly to the computer. Most OBD inspections still include a visual on the catalytic converters. If you have them, and the OBD passes you should be good to go. If they do a "visual" under the hood, I doubt most mods would be readily noticable except for the CAI. In Maryland, they no longer do a visual under the hood, just the OBD and exhaust visual. I have done the DCAI and the Eurocharge ECU Tune and have passed emissions OBD both times. I haven't taken off my cats, nore will I.