P0410 - Secondary air flow malfunction?

I was looking at my step-fathers truck (a little s-10). The check engine light came on and I pulled a P0410 trouble code. The truck only has 60k miles on it, and it has been taken care of. He took it to the dealer who said it was the air pump, and they replaced it. Then a week or so later it came back on, he took it back to dealer, and they replaced air pump again! now the code is back for a third time. He also has a burning smell coming from the engine. It smells like it could be rubber or wire. I checked all the wire and couldnt find any frayed or loose connections. Any ideas? He doesn’t want to take it back to the dealer, but I am affraid my expertise is not in this department.

Thanks, Melissa

If your truck’s design has a check valve like some of the other GM designs, those are what fails more often than the pumps. Follow the hose from the pump to the manifold…

This is probably an electric air pump (you didn’t say what year). The electric air pump would be under the control of the engine computer. The computer, also, opens a solenoid to allow the air from the air pump to go to each cylinder bank (if a V engine) through the metal piping into each exhaust manifold. The secondary air pump injects air into the exhaust to provide oxygen for the catalytic converter to burn any unburned fuel in the exhaust.