they looked under the hood.. the techs out here dont seem too bright and may not have known what they were looking at, who knows. I did remove all the all of the original air intake equipment, so the only thing that looked out of place is the chrome air cleaner. the tech did recognize me from the week before when i came in before doing the swap and found my sammi to be to underpowered to complete the test!! couldn't even hit 58 mph. All i know is it reduced the readings by 2/3 from the test the year before.