New A.I.R. pump doesn't solve P0410 code issue

I have a 2000 Buick Century Custom, 3.1L, automatic. It is failing emmisions testing here in Utah, with the P0410 code. In searching the forums, I have learned that changing the secondary air injection system pump (i.e. AIR pump/smog pump) almost always fixes the problem. Unfortunately it didn't for me.

Are there any other causes of which anyone knows for this code?

Thanks!
Kent.

Welcome to AF

There are basically 4 components to the A.I.R. system that are controlled via the PCM:

1. the A.I.R. pump itself
2. the A.I.R pump relay
3. A.I.R. pump bypass solenoid
4. A.I.R. check valve (to keep exhaust gas from backing up into the pump when it's not commanded on by the PCM)

Any one of these item's malfunction could trip the P0410 code.