Nitrous Purge is a visual upgrade featured in Need for Speed: Underground 2. There are three types of Nitrous Purge upgrades; Type 1, Type 2 and Type 3. Players can select different nozzles for every category. Coloured nitrous sprays are only available for upgrades using every nozzle. Nitrous Purge can only be purchased after installing any Nitrous upgrade. Doing so will automatically equip the player's vehicle with a Type 1 Nitrous Purge.