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_spyder 08-09-2009 09:33 PM

Replacing air box with K&N air filter. HELP
I am going to be replacing my zetec air box with a K&N filter for now. I know I will have to take out the air box and then replace it with the filter, but what do I do with the tube that goes from the air box to the engine.

The hose I am talking about is the hose that the number 4 is pointing to in this picture:

What should I do with it if I am just sticking a filter on?


hammer2.0 08-09-2009 09:57 PM

Are you just replacing the filter element or a complete CAI system? I don't think you can just remove the airbox and put a cone filter on there. That little hose looks like a PCV hose, goes from valve cover to air box. You need this to be able to hook up somewhere on the airbox. If the kit was designed for your engine, then there will be a hook up somewhere, check the kit intstructions. Don't leave it off or plug it, your car won't like it.

Mr.Bergner 08-09-2009 11:26 PM

That's the crank case breather hose that usually recirculates into the air box. Most people, including myself, put a crank case breather filter on the end. Here's my concoction:

I hear what your saying, it seems weird just slapping a filter on the end but essentially that's what I've done here but using a Volant tube instead.

You can pick those filters up at any parts store, I trimmed my hose down a bit

norcalfocus01 08-09-2009 11:47 PM

I did the same thing, slaped on the filter on the stock tube, then the breather filter on the valve cover.

Master-Baits 08-10-2009 12:01 AM

wow your spi underhood looks nice, me likey

norcalfocus01 08-10-2009 12:08 AM

Thanks! Im not rying to brag but I do think I have one of the best SPi bays on here. I need some more updated pics tho.

I also want to paint the heat sheild flat balck along with the timing cover.

Sorry about the thread jacking.

_spyder 08-10-2009 01:08 AM

Alright thanks guys, looks good. I'll be trying this tomorrow! Did you guys notice a difference?

mikebontoft 08-10-2009 01:15 AM

Btw I did the same as them, but I just left the lower box on. That way I still have the useless air snorkel on it as well as not having to bother with a breather valve filter

Mr.Bergner 08-10-2009 02:13 AM

Not sure about the snorkel since I never tested it but I rerouted it using a velocity stack mounted in the lower grill. Used a 3" flexible exhaust pipe to extend it. I put just a low power fan in front of the stack and you can feel a good amount of air moving through and up just under the intake.

dooor 08-10-2009 11:49 AM

How has the K &N worked out for power and fuel mileage? Has anyone done the K & N on a 2007 2.0 pzev Duratec? My cars gas mileage has dropped about two mpg from last summer. Could the 'lifetime' engine air filter be the problem at 40,000 miles? tire air pressure, oil changes are kept up

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