No. The oxygen (O2) sensor is installed in the exhaust system. It is composed of a ceramic element coated with platinum compounds. When it gets to a temperature of about 600 degrees F it will generate a voltage which is proportional to the residual oxygen in the exhaust system. When the engine is running rich, the voltage is about 1 volt and when it is running lean the voltage is about 0 volts. This information is fed back to the Engine control unit (ECU) and is used in conjunction with the input from the Mass Airflow sensor and throtle position sensor to adjust the amount of fuel to be injected. The O2 sensor on your 850 has a built in heater to get it up to operating temperature faster. At startup, before the sensor is up to temperature, the default value is for a rich fuel mixture. By heating the O2 sensor the engine is able to get to optimum operating mixture of gas and air quicker.

The knock sensor are devices screwed into the engine block (Two are installed under the intake manifold on this car I believe.) which generate an electrical signal when there is spark knock. If knock is detected, the ECU will retard the ignition timing. Using a lower than recommended grade of gas can cause knock to occur and the resultant timing change can seriously affect performance and gas milage.

Go to www.howstuffworks.com for some good general information about the basic operation of the various systems in cars. If i remember correctly, there is a pretty good discussion on emission controls and fuel injection.

Hope this helps.

Dan