A poorly running engine could be the result of a bad oxygen sensor. Oxygen sensors measure the air to fuel ratio in your Corvette's exhaust system - which aids your Corvette's ECM in determining whether your engine is running a lean or rich fuel mixture. A bad sensor will report an incorrect voltage to the ECM and cause the computer to adjust the amount of fuel incorrectly. There are many things that can affect the amount of oxygen your Corvette is getting (altitude, humidity, temperature, barometric pressure, etc.), therefore an accurate oxygen sensor is an essential for a healthy running Corvette. New OEM Delphi 1997-2003 Corvette rear oxygen sensor. 2 per Corvette.