Ok my truck is bone stock except for a egt gauge. a couple days ago we got a bunch of heavy rain i mean heavy down poor since then the truck has seemed sluggish there is no codes its defantly not a fuel issue becuase it runs smooth ideals fine no varriation and just did the fuel filter and the truck fired up so its not hte lift pump either and the clutch is not slipping because i can nail it in third and it goes and the rpm seems match to the speeds. and in 6th gear doin about 55-60ish up hill my egt was around 1000deg. any way today i checked the air filter and to my suprise it was wet and got to looking and my factory air box was compleatly loose like rattling around loose and the boot that goes to the fender was not in the houseing it just there and there was the huge whole were it was spoda be. now if durning that heavy rain and fine dust that was on the pre filter foam thats on a wix filter got soaked it would turn to mud and make this truck starve for air correct? and does a factory air box need to be sealed and not have a 3'' whole in the side of the box?

 

I ran mine without the boot from the fender to the airbox for a whole year to see if the restriction it caused changed my mileage. So I don't think the hole is doing any harm, but it's probably not doing any good. Get a new air filter in there and see how it goes.

 

The only time I bought an a paper filter I got a 12v filter without the foam. But some people drill holes in the air box on the dirty side to help pull more air, myself included, and havent had any trouble as a result.

 

i dont think so any more too but i was just seeing if there was any thing to watch out of and because of this is the reason i dont want a open air filter if this small of a whole cause the dust to cake on then man what would happen with a intake setup.

 

i run a BHAF (has no box around it) and have gone through some heavy rain with no water getting on the filter... how fast are you hitting the puddles? seems like it would take quite a splash to get the filter wet! maybe leaving the hole in the box but adding some sort of plate over the fender hole might help (don't block the fender hole, but put something between the fender and the airbox to deflect the water splash)

 

well what i think happend was when that down pour started dumping i think some of the water might have came in were the hood meets the fender and then since the baffle was not were is was supoda it got in thats the only thing i can think of how it got wet but it did and it made a mess out of the foam on the filter.

 

I have the stock box with K&N. I check it whenever I change oil, as I pull the turbo boot, makes it easier. The turbo is always clean(2-3 changes) and performance/ mileage improved a little bit.
The person I got the K&N from said he got abot 70% of what the new BHAF type he got did. He was into heavy Boming.
For me, stock box & K&N work.
My $.02.