Firing all cylinders on your high-performance ride can produce nitrogen oxide, carbon monoxide, hydrocarbons and other harmful gases during the combustion process, which are then released into the atmosphere from your vehicle's tailpipe. Your vehicle's emissions control system is responsible for limiting the discharge of these hazardous gases in the atmosphere. Do your part to keep the environment clean by upgrading any worn-out emissions control system components with durable replacements from AutoZone.