The air injection system is necessary to improve the function of the catalytic system. The air system injects outside air into the hot exhaust system, which allows unburnt hydrocarbons to safely combust in the catalytic converter. This process greatly reduces harmful vehicle emissions.
Air systems are rarely removed but often upgraded. High Flow filters and “Cold Air” intakes increase flow of air to the engine and allow for colder air, which has more oxygen, to reach the cylinder. The increased oxygen burns hotter in the air-fuel mixture and horsepower is increased. Such upgrades are not illegal in Nevada. As long as a system is present and exhaust levels are maintained, light duty vehicle with upgraded AIR systems will pass smog.
If an AIR system is removed, it will be detected by the emissions inspector during the visual inspection, or it will set off the cars Check Engine Light, and fail the test.