P0410B code

my 2001 blazer zr2 is displaying service engine soon. my friends diagnostic tool read the code as P0410B secondary air injection system fault. does anyone have any idea what might be causing this and how to remedy it???

Dont know about yours specifically, but I had a SES on my 98 z28 for secondary Air Injection driver side. I replaces the AIR check valve, which was pretty much frozen up on the inside with exhaust crap, and the code was gone for good. If the blazer also has these small, black check valves that only let air into the exhaust, and not exhaust back into the pump, they might be the problem. That is all i know.
Eric