Non–Ideal Properties of ZrO ₂ and TiO ₂ Exhaust Gas Oxygen Sensors

A brief physical description of ZrO₂ and TiO₂ exhaust gas oxygen sensors is presented, followed by a comparison of the two sensors operating under actual open-loop and closed-loop conditions on an engine/dynamometer setup. The sensitivity of the ZrO₂ sensor to engine load and cylinder-to-cylinder maldistribution is explored, and the compatibility of the ZrO₂ switch point and a three-way catalyst window is considered.