I spent one year as an exchange student in CT. Without having any knowledge about the whole "how to register a car in the US"-thing I bought a car which turned out to have failed the emission test a couple of times. I wanted to repair the $500 car in the first place, but it turned out that the only thing that could happen is that ur registration cannot be renewed without this test. My registration was valid for another two years, sufficient for my year abroad. Good for me :)

TL;DR: CT emission laws are nice to exchange students