It really depends on the state. Here in AZ I not only have to pass emmisions, but what they inspect is apparently up to the discretion of the actual inspector. When I asked for a hard copy of what I was to be tested for, I was handed a book, and told "It's in here", but no where in there did it list SPECIFIC requirements. This state took a cue from CA, and ran with it... I was originally told there would be no equipment inspection, then they failed me on my gas gap and did a "visual ispection" on my Vapor canister. When I went back for the retest, they never even looked at it or opened the hood... I hate Arizona's emmisions program...
bill