My check engine light came on and the read out indicated the oxygen sensor needed to be replaced. I've got the sensor but cannot locate it on the engine. It is not where the clerk at the parts store said it was. Any body out there changed one out lately and can give me a clue?

thanks,
PC

 

the car has 2 of them. 1 on the exhaust pipe Before the cat converter and one on the rear of the cat converter. You need to go under the car to see them

 

Thanks for the tip. The car failed emissions inspection today. Which sensor would be the most likely to be responsible if indeed that is the problem?