Patent ID: 8236155

Claim:
An exhaust gas sensor that is multilayered and exposed to a space in an exhaust path of an internal combustion engine, the exhaust gas sensor comprising: an electrolyte layer which is positioned between an exhaust electrode and an atmosphere electrode to permit the movement of oxygen ions between the electrodes; an atmospheric layer formation layer which is placed on the atmosphere electrode side of the electrolyte layer to form an atmospheric layer to which the atmosphere electrode is exposed; a diffusion resistance layer which is porous and placed on the exhaust electrode side of the electrolyte layer to control the flow rate of an exhaust gas reaching the exhaust electrode; a shield layer placed on top of the diffusion resistance layer defining a gas inlet/outlet section of the diffusion resistance layer so that an inlet/outlet for the gas flowing into the diffusion resistance layer is limited to the gas inlet/outlet section of the diffusion resistance layer; and a trap layer which is porous and formed to cover portions of the sensor exposed to the space in the exhaust path; wherein the trap layer includes a first trap layer, which covers a region overlying the gas inlet/outlet section of the diffusion resistance layer, and a second trap layer, which covers a region that is not covered by the first trap layer and at least overlying the atmospheric layer formation layer, the first trap layer being thinner than the second trap layer.