Secondary Air Injection Insufficient Flow Error - Help Please

2006 Audi A8 with Secondary Air Injection Low Flow Error. Looking for help. Vacuum lines between the 2 Combi valves and the Inlet Valve have been changed as well as the Inlet Valve to the front of engine where it gets vacuum from the intake manifold. Have used VCDS to tested functions of blower motor, blower relay, inlet valve at rear of engine and front of engine and all seem to make the correct noises. Also, did the Audi Service Manual procedure to test the combi valve and air is flowing freely once the combi valves are opened via vacuum pressure.