| 摘要 |
PROBLEM TO BE SOLVED: To provide an air-fuel ratio sensor capable of preventing the poisoning of a detection element due to influence of a protective tube and appropriately determining a cylinder which causes imbalance, and to provide an imbalance determining system using the same.SOLUTION: An air-fuel ratio sensor 1 for imbalance determination includes a detection element 10, a cylindrical housing 50 which surrounds the circumference of the detection element, a cylindrical case 65 connected to the rear end side of the housing, a lead wire 64 which is electrically connected to the detection element and is taken out from an inner part of the case to an outer part, and a protective tube 68 with which the lead wire is covered on the outer part of the case, and determines the imbalance of the air-fuel ratio between cylinders #1 to #4 of a multi-cylinder internal combustion engine 100. Therein, the protective tube is prepared by coating the surface of a braided body of glass fiber with acrylic resin or is made of a braided body comprising polyphenylene sulfide fiber and polyether ether ketone fiber.SELECTED DRAWING: Figure 2 |
