Secondary Air System malfunction

I have a 2001 GMC Sonoma 4x4 and the check engine light is on. The code is P0410. This codes means Secondary Air System Malfunction. We ordered a new air pump & new hose assembly from GM. The pump even had a new vacumn switch with it. Check engine light right back on! So we replaced the two fuse under the hood behind the battery.( Max 30A & Typical 10A) Check engine light back on again! So we bought the two one way exhaust check valves on each side of the motor and the whole new hose assembly attached to it, that connects to the air pump. Check engine light back on again! This is really upseting me. We can't figure out what to do to get the light to stay off. I researched it on the internet & have done exactly what everyone has reccommened! Can someone out there please HELP!!!!!!! After $500-$600 I still have the same problem!!!