Air-fuel ratio detecting device

摘要

An air-fuel ratio detecting device with which the air-fuel ratio can be accurately detected over the entire range of ratios, both for the lean range and for the rich range. An oxygen pumping element and an oxygen sensing element are arranged opposite one another with a gap therebetween and are disposed in a chamber in which exhaust gas flows. A signal which is symmetric in lean and rich regions is thereby obtained, and this signal is divided into separate portions in the two regions, which are then composed to obtain a single-valued signal accurately representing the air-fuel ratio over the entire operating range.