Faster response time improves wideband feedback control, and can provide a safer, more powerful and accurate tune. AEM's Wideband Controllers with X - Series digital technology can reduce deadtime and improve the performance of your vehicle through more accurate AFR tuning. Deadtime is the delay between when exhaust gas composition changes and when that change is reported by the O2 sensor. While flow of exhaust gases (transport delay) can affect deadtime, it is not the only source. Often, the sensing elements response to the gas is the largest contributor to deadtime when an engine is in high RPM under load.