Recently purchased an '02 35th Anniversary edition SS with 90k mikes on it. All stock except for Borla exhaust. Only change I've made so far is an SLP air box lid. Have only driven car about 100 miles since I got it. Yesterday, "Service Engine Soon" light came on. Took it to Auto Zone and scanner showed P0410, Secondary Air Injection System as well as P0420, Catalyst System Low Efficiency (Bank1) and P0430, Catalyst System Efficiency Below Thershold (Bank 2).
This morning, disconnected the hose running over the fender well at the union, started the car and let it idle for about 6 minutes and got no air flow from the hose. Then disconnected the hose coming out of the air box and got no suction, so the air pump was not working. I think I read somewhere that it should come on within about 3 minutes. Other than the location of the pump and check valves, that's about the extent of my knowledge on this system!
What turns the air pump on? What should I do next?

 

Here are pages from the 2000 Service Manual that help troubleshoot the DTC's you listed. I'm pretty sure they are the same as the 2002 Service Manual. Hopefully, they will help explain the conditions necessary to set the codes and how to determine what caused the problem.

 

Thanks.

 

Hi PeterPar,

Hoping you can help. Like mikey444, I recently bought a '02 SS SLP. The Service Engine Light was illuminated when I bought it.
I took it to State inspection and failed. The OBD II reader diagnostic identified the following:
P0410: Secondary Air Injection System
P0412: Secondary Air Injection System Switching Valve A Circuit

Emissions Result
MIL Commanded FAIL

When I got home, I also pulled the air hose that runs along the front driver side fender. Started the engine and felt a steady stream of air flowing so I at least
know the Air Pump is working. Any idea on what this code means: (P0412: Secondary Air Injection System Switching Valve A Circuit)?

Thank you!!

 

I don't know if I can be much help with your problem. My experience with solving DTC code issues is limited to my own cars and I have had very few of them over the years. Something that I have found helpful is a copy of the service manual and a GM Tech 2 scanner. The manual will have an explanation of the code and what conditions will set it, plus a chart to troubleshooting it. The DTC P0412 code pages below are from the 2000 service manual, but they are the same as 2002. Hopefully, they can help. A 2000 Service Manual can be downloaded at this link.

 

That's a big help!

Thanks again!

 

You may have to buy a Harbor Freight OBD2 Code Reader thus having the option of reading codes and deleting them.