Will an O2 Sensor Work Without a Catalytic Converter?

The in-cat or after-cat O2 sensors are just used to check the efficiency of the cat itself. Therefore, in most modern vehicles a car can run just fine without a cat.

Can oxygen sensor work without a catalytic converter?

an O2 sensor does not need a cat to function properly. There are aftermarket fuel injection systems that use an O2sensors to keep fuel mixture anywhere you want, usually way richer then is safe with a cat. The sensor just reports free oxygen, the software it reports to does whatever it's written to do.

What happens if you don't have a catalytic converter?

Harmful Car Emissions

Your catalytic converter is named as such because it converts toxins into less harmful byproducts, such as water vapor and carbon dioxide. Without this component, your vehicle will no longer be filtering and reducing harmful emissions, including hydrocarbons, nitrogen oxides, and carbon monoxide.