What is an 02 Sensor?

The Engine Management Light comes on when driving and I am told the fault is that an 02 sensor requires changing? What is an 02 sensor?
Vauxhall Astra 1.4 '94 model
Mary-Anne Lobo, May 2005


done
I have never heard of cleaning a o2sensor .....some cars incorperater as many as 3 in a system ....pre convertor ect.
Monitors fueal exhaust so computer can either rich or lean mixture ,,,,,

bg, November 2005
o2 sensor senses the amount of oxygen going through the exhaust , not into the engine. the more oxygen in the exhaust the weaker the fuel mixture is, so it provides the ECU with feedback on how correct the mixture is. they are a common problem for setting of the engine management light and if you have been reliably informed that this is definately whats wrong in your case then replace it, dont bother cleaning it. it will be attached to your downpipe.

mike, October 2005
an 02 sensor is a sensort that measure how much oxygen is going into the engine. It sounds like the sensor has gone faulty or simply needs a good clean. Best to clean it first and then replace if check engine light still comes on

vw, May 2005
link Click here to see other fixes for Vauxhall Astra.