[Taliyahk]

I have an corsa cat back exhaust and didnt get the NPP version even tho stock I came with NPP. I changed my exhaust a year ago and just still kept the AFM valves plugged in and zip tied out the way and its never been an issue. However now I have that code and my exhaust sounds funny ands car has a little rough idle. Any suggestions on what it could be or what I should do? Someone told me I may be a lifter and ima need a new cam etc? The CEL went away not sure why but the problem sit exists and the cat is kind of put puting a bit like a misfire. -2023 SS-. (Also I think this happened when I put my car in snow:ice mode and I never really do)