Secondary Air Check Valve Replacement on 2015 GMC Terrain

[katsaccount]

Check engine light came on for the secondary air check valve. Replaced the air check valve and the check engine light came back on. Have been now told that it could be that there is carbon build up that needs to be cleaned out on a hose or line that is connected to the air check valve. Does that sound correct?
Thank you

 

[clinebarger]

Buy tuning software & turn the DTC's off if you don't live in a CAFE standard state or you don't have emissions testing to begin with.

 

[Dave Sherman]

What code are you getting, specifically? Had a 2013 Equinox with the 2.4, the SAI code P0411 for low or insufficient flow kept coming up. I confirmed the pump was running and the check valves were sooted up, I replaced the valves but the code came back. The carbon build up in the air injection ports is a known issue. There is no permanent fix, the exhaust manifold has to come off and the carbon has to be cleaned out by hand when they clog up. I paid the man to do that and he found the exhaust manifold was cracked too, another known issue. $1200 later both problems were fixed.