About reprogramming ECM on my 05 Honda civic?

My malfunction indicator lamp went on just a few days ago. Took it to AutoZone to get it checked out. Gave me a paper saying something about reprogramming ecm. I need help on this matter. My car is working pretty fine and good. AutoZone guy said you won't feel it while driving and I should be okay. I want to know more details about it before I try taking to my dealer.

Take it to honda they have to flash it with there goods

What was the code? I wouldn't trust an Auto Zone salesperson to tell me anything! If they turned the light out just drive until it comes back on, if it even does come back on. Try going to Advance auto if the light comes on and write down the actual code and post it here.