they did a visual outside and they looked inside for the obd thingy. they also looked under my car, i think he was looking at the cat or something. He did a more thorough check under my hood checking wires plugs and stuff. he didnt use a sniffer. just a flash light haha. he was pretty cool. he wasnt a prick or anything like that. and after the visual they did a smog. oh and he scanned the inside of my car for the vin #. ummm... thats about it. he also asked me what i got a ticket for. i said i dont know, some filter haha. then i said, " but i had an AEM cold air intake." then he said, "you should have just left it on." haha i dont know if he was being sarcastic or not.