Go hear to the MD site: VEIP General Information
The type of test depends on the year of the car. Assuming yours is a '96, you'll have to do the ODBII port test type. The ODBII test has two parts to it.
The first is the ODBII test which just checks for CEL codes. As long as your 02 censors are on and reading "Ready", you should be ok for the ODBII check.
The other thing is that they walk around the car with a mirror attached on the end of the a stick looking under the car for cats or other illegal modifications. The visual check really depends on how hard the inspector wants to look and how much they really care.
'05 GT - Borla Catback, JLT Series 3 Intake & SCT SF3 Tuner, Koni Adjustable Shocks/Struts, H&R Race Springs, Roush Shifter, Hawk HP+ Brakes all around, Steeda Front Sway Bar & End-Links, Royal Purple Fluids
'2011 F-250 Super Duty Crew Cab - 6.7L PSD 4x4