Ok, so based on all the comments, and that it's probably the oxygen sensor or something like that, I'm assuming that I still need to get it checked at AutoZone, correct?

Just some history, I bought this car used about 3 yrs ago. Within about 3 mos of having it, the check engine light came on and, really, it has been on steady up until recently, when it's been going out. You'd think the bulb itself would've gone out by now - haha. Maybe that light runs on something charged by the battery, though, and it never burns out. Anyway, I don't know why it's been going off and on - that's a new thing. And it has always passed inspections up unitl now where apparently this new law has been passed.

Next action - read the code and go to AutoZone?