But it will raise $$$. Just another tax.
In Connecticut it was a loser. By statute, the fee for a test is $20 -- half to the testing station and half to the state. If you fail, the first retest is free.
For an OBD-2 vehicle, the test is quick -- run the mirror underneath to verify that the cat is still there, plug in the scanner to the OBD-2 port, fire it up and read the numbers. For any pre-OBD-2 vehicle they have to physically do a pressure test on the fuel cap, they have to put the vehicle on a chassis dyno and actually run the vehicle through a prescribed series of operational parameters. And then do it again -- for free -- if the first test failed. I'm sure the shops doing the testing were losing money hand over fist, and even the knuckleheads in Hartford finally realized that all they were doing was causing testing stations to leave the program.
MD is almost the same, sans the dyno. We have tail pipe sniff test. Just run the engine at 2500 RPM for 1 minute. If you fail, next test is free!
Cost us $14 every second year.
I could put "historic" tags on it (20+ years) and not have to have the testing done. However, there are restrictions on amount of driving you can do with the vehicle (not a DD). The historic tags cost more every two years than regular tags. Not much of a savings.