There are two basic types now in use; the narrow-band Lambda sensor, and the broadband sensor.
The narrow-band Lambda sensor only detects the presence or absence of oxygen; its' output signal varies from roughly 0.1v to roughly 0.9v. It's basically a "yes" or "no" type of thing, and the ECU is constantly seeking back and fourth from too rich to too lean in order to keep the engine running near stochiometric (14.7:1 air/fuel ratio by weight).
The newer broadband sensors can accurately report the actual air/fuel ratio detected in the exhaust. They are not interchangeable. They sort of work opposite to the older lambda sensors.
The narrow-band Lambda sensor only detects the presence or absence of oxygen; its' output signal varies from roughly 0.1v to roughly 0.9v. It's basically a "yes" or "no" type of thing, and the ECU is constantly seeking back and fourth from too rich to too lean in order to keep the engine running near stochiometric (14.7:1 air/fuel ratio by weight).
The newer broadband sensors can accurately report the actual air/fuel ratio detected in the exhaust. They are not interchangeable. They sort of work opposite to the older lambda sensors.