i had the same problem on my 08 SE. no affordable intakes. i search the forums for a few days and found a great trick that works awesome on my 08 Focus SE.
first, buy a OEM drop in K&N for your focus. paper i just crap.
second, look inside your airbox with the filter out and top part off.
its pretty deep. at least my SE is. your ST should be the same. take out your airbox. cut the very bottom of your airbox off. i used a rotary cutter and it took 2 minutes.
Boom cold air intake for free. well free if you already had a K&N in it. otherwise $45. it even has that deep sexy sound the real intakes do and it really made a difference. more throttle response on takeoff and when i punch to pass you really feel it.
have fun
The fuse box on the Ford Focus is actually located behind the glove compartment. Open and empty the glove compartment and pull out the back panel to expose the fuse box.
Under the air box.
The ford focus has a second fuse box at the rear of the glove box. You must empty glove box, when the glove box is open push in the sides,it's not easy and you must force it open. Its easy after that you will see whats what. Its a 15amp if that helps.
The exact location of the Ford Focus air conditioning relay switch is dependent upon the year of the automobile. In most cases the air conditioning relay switch is located in the fuse box.
who is the location of the fuse box of ford focus 2004? fuse box ford focus 2004 location
In the air filter box, under the hood, driver's side, behind the headlight area.
As far as I know it is located under the air filter box.
open the glove box then cut the back out of the glove box then shine a flash light in to the engine compartment and there they are.
You can locate the 2002 Ford Focus IAT sensor on the hose between the air filter box and the top of the engine. The IAT sensor will be labeled as such.
Mine was in the bottm corner of the plastic box that holds the air filter
Those heavier fuses are in a box, on the driver's side, up by the firewall.
The 2005 Ford Focus has a air cleaner in the drivers side front wheel well , which is supposed to last the life of the car. It still has the old type air box with no filter element in it, which is what you are seeing.