failed emissions test

being that this is an obd2 computer system , normally if there was any type of problem , the computer would turn on the check engine light.. i am not sure how they test emmissions in tn, but they should just plug into the computer and check for codes , if there are none you should have passed. if they are checking at the tailpipe , exhaust emmissions , make sure your car is up to operating temp, keep running if you are in line ,, the hotter the better , also make sure that the engine is getting hot enough, make sure the temp gauge is at least halfway up , ( meaning that make sure your thermostat is working properly..

They check it at the tailpipe. the radiator fan was running only for a few seconds. thanks for the info. i'll check the thermostat.