{
  "$type": "site.standard.document",
  "description": "Method and apparatus for monitoring a catalytic converter (32) during engine (catalyst) warm-up by first and second heated exhaust gas oxygen sensors (60, 70) located upstream and downstream, respectively, of the catalytic converter. A microprocessor determines a change of signal output of the…",
  "path": "/patents/1111680",
  "publishedAt": "2001-07-11T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N11/007",
    "FORD GLOBAL TECH INC [US]"
  ],
  "textContent": "Method and apparatus for monitoring a catalytic converter (32) during engine (catalyst) warm-up by first and second heated exhaust gas oxygen sensors (60, 70) located upstream and downstream, respectively, of the catalytic converter. A microprocessor determines a change of signal output of the downstream sensor relative to signal output of the upstream sensor during engine (catalyst) warm-up initiated by engine cold starting during the catalyst warm-up period. A catalyst light-off temperature is determined by the microprocessor when the change occurs. The catalyst light-off temperature thus determined is compared to a stored reference catalyst light-off temperature that is indicative of a properly functioning (e.g. fresh) catalyst to assess the extent or degree of degradation of the catalyst.",
  "title": "Cold start vehicle catalyst monitor"
}