Added a K&N intake and a flow master muffler - since then my 2019 Silverado has started shifting a little rough at low rpms. MAF sensor need cleaned? Re flash ECM? Just unhook the battery to reset?? It is not throwing a code.

 

You might need to drive it a bit to relearn, after all, you did just make some minor adjustments to how the engine breathes. I've personally have been skeptical of CAI, but the free-er flowing exhaust can help...