You will need a scan tool with output test activations ability to diagnose the problem. You need to activate the AIR pump to test anything. Disconnect the AIR hose from the pump to the switching valve. Activate the pump. Is there good air flow being coming out of the hose. If so, then reconnect the hose and run the pump again. See if you can hear or feel any air flow coming out anywhere (you are looking for a leak in the hoses). If neither one of those tests shows a problem, give me your email and I will email you the whole diagnostic chart for that code. My email is ChevyASE@aol.com
Thanks I am a mechanic by trade (School Bus right now)so I do have that tool but went to the dealer and they said it might be covered by GM emission warranty. Will find out Monday if so we will take to them. I will let you know how it turns out if it is not covered I will try your answer. It said secondary air injection system switching valve stuck open bank 1 when I got the code. Our email is firstname.lastname@example.org.