It's insane how many people have this same problem. Searching online web wide and at other GM vehicle forums, this problem is rampant! Example: http://www.gm-trucks.com/forums/topic/173303-secondary-air-injection-monitor-will-not-run/page-2
Quoting: "I just bought 2001 GMC Sierra with the same damn problem..extremely frustrating. I've completed several fresh drive cycles in the last few days to no avail..however, when I first brought the truck in to the smog center this morning the tech said it completed. Then when he "double checked" it before running the actual smog, it failed...this left me confused and a little pissed off..."
Quoting: "I just bought 2001 GMC Sierra with the same damn problem..extremely frustrating. I've completed several fresh drive cycles in the last few days to no avail..however, when I first brought the truck in to the smog center this morning the tech said it completed. Then when he "double checked" it before running the actual smog, it failed...this left me confused and a little pissed off..."