honestly the states emissions program is a money making scheme that keeps the tree huggers happy as a bonus. I wouldn’t be surprised at all if the state did away with tailpipe testing within the next few years. the machines are old and the parts are getting harder to find, every year shops loose the ability to tailpipe test because the machines break down and can’t be fixed. now that OBD II is 12 years old there are less and less vehicles every year that need tested and the state is starting to realize this. in our shop we might see 1 tailpipe test a month
it’s actually very straight forward it just gets confusing with different regulations for different areas. emissions testing in philadephia is pretty different for certain years than out here