Fault Code P2431
I post here very occasionally on behalf of my son who owns a 2007 Cobalt LT sedan. It He now has a fault code P2431. I've tried to research it online. There seems to be several tings which can cause this fault code. His fault code indicates "secondary air injection system air flow/pressure sensor circuit range/performance bank 1".
What components can be involved? Should we just replace the secondary air injection system air flow valve? Or can it be more complicated or other things involved?
Thanks for any advice and help on this.