I called my mechanic he said it takes three hours to change front end o2oxyen sensor.i have 2007 Ford Fusion

I called my mechanic he said it takes three hours to change front end o2oxyen sensor. I have 2007 Ford Fusion

This should never take 3 hours. In fact, it shouldn't take longer than an hour. Ask him what all will be done in those three hours.

Look it up on you tube and see

Ask other mechanics. It does sound excessive to me. The O2 sensor is simply screwed into the exhaust pipe. Unless he's got to virtually remove the engine to do it, which I doubt, he's having a laugh.