RE: What is an O2 sensor---what does it do? Anyone-newb
RE: What is an O2 sensor---what does it do? Anyone-newb
An o2 sensor, or oxygen sensor, is attached to the exhaust system and senses oxygen in the exhaust to tell what the air/fuel ratio is. Normal oxygen sensors aren't very precise, they can tell you if the engine is running rich or lean, but not how rich or how lean. A wideband o2 sensor will tell you exactly what the a/f ratio is.
A solenoid is a device that converts electrical energy into motion to open or close a valve or connect/disconnect another higher current electrical circuit.