It does not have secondary air injection.
While the question doesn't make much sense, the secondary air injection system on a cobalt is fairly simple. If you could give an exact code the answer would be much easier to figure out.
There are several ways to fix the secondary air injection system in a 2005 Chevrolet trailblazer. The most common fix is; changing the air filter.
Some GM cars have this code but no secondary air, has it been worked on?
The secondary air system pump is on the driver side below the battery .
Need to know what your question is.
it has to do with secondary air injection
Without knowing what is wrong with the system there is no way to determine the cost.
right under the alternator below the air filter
On the exhaust manifold the small stainless steel tube is attached to secondary air injection valve. This tube can become restricted and clogged with carbon causing a CEL code. It needs to be cleaned out.
the secondary air injection system on a 200 Chevy s10 is right by the radiator on the passenger side of the engine bay. if you look down there are 4 bolts bolting it to the frame of the vehicle.
Secondary air injection pump is located right on top/front of your engine. Its a black pump which should have a aluminum bracket holding it on. Just one inverted torx bolt and the electrical connection