I'm going through all the BS trying to get my Nissan Xterra registered here in Maryland and one of the things I have to do is get it safety inspected, which should also include the emissions check. Unfortunetly, recently my Xterra posted a service engine soon light and when I borrowed my friends OBD II reader to check it out, it gave P0455, or a EVAP system gross leak. I made sure the gas cap is secured (a common cause of the problem) but after resetting the code, it came back shortly there after. According to online sources, I need a smoke machine to properly diagnose it. Most reputable shops should have one but being new to the area, I'm hoping I could get some advice. Another friends get's his Xterra serviced at the dealer Tishler in Laurel, but looking online, the reviews are not good.