Secondary Air Injection Issues
Model: 2008 Chevy Cobalt LT
-P0441: Secondary Air Injection System, Insufficient Air Flow Detected
-P0651: Sensor Reference Voltage B Circuit/Open
The first code used to only come on in the winter any time below freezing (assuming it was getting stuck open or closed) and would go away once it got warmer outside. After this past winter, it's stayed on all the time. Unfortunately, around the spring time I started having an issue where I would start the car and within seconds it would go into "Engine Power Reduced" mode and start shuttering, and that's when second code would appear.
It only goes into Engine Power Reduced mode on the occasional cold-start, which I'd assume could be linked to the first code when the Secondary Air Injection system runs. Basically, if the Engine Power Reduced mode doesn't happen within the first 30 seconds of a cold-start, it doesn't happen.
Do you think this could be as simple as replacing the Secondary Air Flow Injection system, or do you think this might be a much deeper problem? Any suggestions or troubleshooting tips would be greatly appreciated!