Secondary air injection system?

The check engine light came on in my '99 Mustang LX, so I plugged in my dad's diagnostic computer and it gave me the error "Secondary air injection system incorrect flow." Anyone know what this means, and how I can fix it? It doesn't seem like a serious problem; the car runs great and it's never given me any problems, but it is irritating me.

try disconnecting the battery for about 10 min., then reconnect, and drive the car in town for about 15min, so the ecu can relearn......retest code......sometimes when it is cold out, the car will pop off with wierd codes..........hotwheels of turborides.com

I believe thats the smog pump. Have you done anything to the car?

Besides changing oil/filter and brakes (original pads when I bought it.... eurgh), nope. The light came on before I did that anyway.