When the computer receives a rich signal (high voltage) from the O2 sensor, it leans the fuel mixture to reduce the sensor's reading. When the O2 sensor reading goes lean (low voltage), the computer reverses again making the fuel mixture go rich.
Chemistry and physics are branches of science that both study matter. The difference between the two lies in their scope and approach. Chemists and physicists are trained differently, and they have different professional roles, even when working in a team.
1 Physical chemistry has a large overlap with theoretical chemistry and molecular physics. 2  Physical chemistry involves the use of calculus in deriving equations. 3  Theoretical chemistry is the study of chemistry via theoretical reasoning (usually within mathematics or physics).