I am not sure if the butterfly valve has ever opened

Has two exhaust outlets. One outlet has a closed butterfly valve about 8" in from the outlet. What makes the valve open? Have used sport mode, green mode and have used wide open throttle. The inside of that exhaust outlet is still shiny and new looking while the other open exhaust is black inside from use. Don't think the butterfly valve has ever opened. It's a north American car if that makes a difference. Had one person say all north American cars have the valve permanently closed for emissions?