Heated oxygen sensors

The heated oxygen sensors monitor the oxygen content of the exhaust gases. Readings are fed into a control module that continuously monitors engine functions and controls fuel injection. The ratio of fuel to air into the engine is continuously adjusted for efficient combustion to help reduce harmful emissions.
See also:
Changing a wheel
Location of jack and tools ...
Vanity mirror
The light comes on when you open the cover. ...
C70 in the Market
The C70 is a good luxury convertible, but it's in a class where good might
not be enough. Competitors — notably the Mercedes-Benz E-Class — do a better job
of protecting those in the car from buff ...
