The PowerStay is a simple plug-in module that eliminates the annoying Auto Start-Stop and/or cylinder deactivation (V4 mode) on many newer model vehicles. Although these features are touted as fuel mileage-improving features from the factory, many customers see no improvements or even worse, mechanical failures due to these features. The Hypertech PowerStay puts an end to these modes on your vehicle once and for all so you can enjoy your vehicle as it should be.