Volvo: Volvo Secondary Air Intake, sas system, volvo 850

Question
Ray,

I have a '97 Volvo 850 with the "check engine" light on.  I took it to Auto Zone so they could hook it up to their device that reads the check engine codes.  The results said it was a Secondary Air Intake issue.  Any ideas what I can do to fix this?  

Thanks for your help.

Greg

Answer
Greg,
Volvo calls this system the SAS secondary air system. It is a system that will under certain conditions pump air into the exhaust system to aid in the heating of the cat converter. The system will need to be diagnosed and the defective parts replaced. Most of the time the pump and SAS valve will need to be changed. The valve will stick open causing mositure to enter the pump and seize it up. There is also a relay that operates the pump, however it has a slightly less failure rate. You will need to have your vehicle checked by someone that is knowlegable about this system, and has the scan tools that will read the codes and activate the compontants as needed. In the scanner there is an area that will allow the tech to turn on the pump and also activate an area the will run a diagnositc test on the SAS system to monitor it's function.