908850
It means Evaporative Emission System Leak. Start with the gas cap. A loose gas cap can cause this.
Trouble code P0171 means:System too lean (Bank 1)
The code refers to the front oxygen sensor on bank 1. That O2 sensor needs to be replaced or the wiring has come loose or is shorted out.
There is a Diagnostic Trouble code set. You need to goto an autozone or other auto parts store and have the code read, or goto a GM dealership and have the code read.
It means the ECU has detected a problem with the emissions system. Have the ECU scanned with an OBD2 scan tool which will retrieve the code. This code will tell you where to start looking for the problem.
If a knock sensor was bad, the check engine light would be illuminated and the code(s) set would indicate so.
Trouble code P0601 means:Internal control module memory check sum error Trouble code P0602 means:Control module programming error
These codes can be caused by aftermarket scan tools and also by unpluging the scan tool with out turning the key to the off possition.
under the hood in the fuse compartment there.....that is linked to the port where you get your codes read from so if it isn't working you can't read a code.
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.
It might be in the inside of the drivers door jamb, or in the trunk by the spare tire look for exterior paint code designated -bc/ cc this number can be cross referenced by your local auto paint supplier or your dealer.