{
  "$type": "site.standard.document",
  "description": "An oxygen amount (an oxygen storage amount OSA) stored by metal cerium during a storage cycle is obtained basis on an output value of an A/F sensor 18 in a time period immediately before an exhaust air-fuel ratio (a downstream side A/F) detected by the A/F sensor 18 shifts to a lean region, and…",
  "path": "/patents/970708",
  "publishedAt": "2014-09-03T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N11/007",
    "TOYOTA MOTOR CO LTD [JP]"
  ],
  "textContent": "An oxygen amount (an oxygen storage amount OSA) stored by metal cerium during a storage cycle is obtained basis on an output value of an A/F sensor 18 in a time period immediately before an exhaust air-fuel ratio (a downstream side A/F) detected by the A/F sensor 18 shifts to a lean region, and degradation relating to OSC of the three-way catalyst is detected. In the storage cycle, a target air-fuel ratio is set so that an air-fuel ratio of exhaust emission flowing into an S/C 14 changes from rich to lean. Therefore, the downstream side A/F shifts from stoichiometry to the lean region at a time t 1 after reaching stoichiometry. When the three-way catalyst degrades, the downstream side A/F shifts to the lean region from stoichiometry at a time t 4 . Therefore, the calculated oxygen storage amount OSA becomes extremely smaller as compared with that at a normal time.",
  "title": "CATALYST-DEGRADATION DETECTION DEVICE"
}