Couple of Questions...

My fiance has a 96' Ford Contour V4 and she bought it from her aunt for $500.00 which is an awesome deal but any how, the only thing that was wrong with it was it needed a new Oxygen Sensor. What are the tell tale signs of that goin' out? Her cold starts are smooth but once it starts it sounds and runs like crap till it warms up. I have a Taurus and I know its typical for a car not to run at its best when started at 14F, but it seems like her Contour needs some work? Acceleration is getting really bad too, it has a time lapse when "hammering" it to catch up and even then it doesn't seem like it should have the slow acceleration it does. Any thoughts?

have you tried plugs and wires?

has your gas mileage gone noticeably down hill?

Yeah I was thinkin' about plugs and wires, the gas milage has been bad lately as a matter of fact. How hard is it to replace a wheel bearing? It is the front right one. How long can she go without replacing the oxygen sensor? And what kind of effect does it have on the cars performace? I really appreciate the help this forum provides.

I don't know much about a wheel bearing, but one of my o2 sensors has been out for a while and I see no difference, I think that's alot of emissions crap.