Abstract: A device, method of making, and method of using, illustratively wherein a container includes an inlet and an outlet; a catalytic converter intermediate in a path between the inlet and the outlet; at least one surface arranged to ensure at least a majority of gas received from the inlet traverses a first portion of the path from the inlet to the catalytic converter and communicates heat from the catalytic converter to the container; and an optical indicator arranged to indicate outside the container whether the catalytic converter is operating inside the container to reduce concentration of a smog-generating chemical with respect to the gas.