focus on is correct
You can not replace it unless it's an old ford focus.
how to replace water pump on 2001 ford focus
how to replace a front fog light on a ford focus
at is the cost to replace a blower motor on a ford focus
In the top radiator hose fitting opposite the radiator, on the engine.
How much does labor cost to replace a shift solenoid in a ford focus?
Tools needed to replace front brakes 2002 Ford Focus?
Yes
Check out the related link for a video on how to replace a crankshaft position on a Ford Focus SE.
It will cost you about $743.00 to replace a vacuum tube on a Ford Focus 2002.
The likely word is focus (to create an image, or to concentrate).