This isn't always true, as there are O2 sensors available which do not rely on temperature to drive the metering and have very rapid response times (these are called wideband O2 sensors, where the wideband part refers to the band of air/fuel ratios in which the sensor is accurate - stock sensors are narrowband). Unfortunately, these wideband O2 sensors typically cost several thousand dollars US!, and actually using them would cost several thousand more for custom installations, but the usage of these sensors can be purchased at dynograph facilities during tuning sessions.