1990-1995 Corvette ZR1 Oxygen Sensor Assembly

How Does does my 1980-1996 Corvette O2 Sensor function?

An early 1980s version oxygen sensor has two wires: One for sensor ground and the other for ECM voltage signal. The second version used one wire. The exhaust serves as a ground. More recently, the O2 sensor has three or four wires. These are called heated sensors. The purpose of the O2 sensor located in the exhaust is to monitor the amount of oxygen (unburnt fuel) left in the exhaust. The oxygen sensor sets up a 100 millivolt to 900 millivolt signal across the inner ceramic thimble that is lined with platinum. This voltage is sent to the ECM (Electronic Control Module)(Power Train Module) so it can adjust the fuel mixture trying to obtain a 14.7 to 1 air fuel ratio. This ratio is called Stoichiometry (the idle air to fuel ratio for a combustion engine).

The O2 sensor must get to a specific temperature of 600°F in order to perform as it should. This allows the ECM to go closed-loop. Closed-loop system means the ECM is controlling the engine relative to various input signals. After a specific throttle angle, the O2 sensor signal is not looked at by the ECM. The ECM regulates the fuel for best performance not trying to maintain a 14.7 to 1 air fuel ratio.

After a lot of city driving the O2 sensor may carbon-up and may cause the engine to surge at idle. After the engine is warm, about once a month or as needed, place the transmission in neutral or park and hold the engine at about 2,000 RPMs for two or three minutes. This burns off any carbon and lets the O2 sensor work properly.