Based on the control of the HO2S heater, a stabilized oxygen concentration is detected even at low exhaust temperatures, and feedback control of fuel injection even at cold engine start is made possible for improved cold temperature exhaust emission performance.
Both emission performance and sensor protection have been improved by duty control of the heater according to engine operation conditions (exhaust gas temperature)
The PCM operates the HO2S heater based on the following control conditions.
| Output duty ratio | Control condition |
| 0% |
|
| 30―50% |
|
| 0―100% (Determined by engine speed and charging efficiency) |
|