ZEX Nitrous Systems for Tuner vehicles incorporates the patented Active Fuel Control Technology, which monitors the nitrous bottle pressure and adjusts fuel enrichment to achieve the perfect mixture. This ensures your engine will never run too rich or too lean when you engage the nitrous system. ZEX nitrous activates at wide open throttle using an electronic switch that monitors your engines TPS sensor. The design ensures that your nitrous is engaged at the perfect wide open throttle position every time. Only works properly with fuel injected return-style fuel systems.