Fig. 317. The oxygen sensor of the Zetec-SE engine is directly on a final collector under the heat-shielding screen

The oxygen sensor a lambda probe is established on the Focus car directly on a final collector (fig. 317) . To lower time for measurement, the oxygen sensor has additional electric heating. The lambda probe measures concentration of oxygen in the fulfilled gases. Signals from the sensor arrive in the electronic control unit. Depending on them the control unit influences structure of a working mix (poor or rich).