I found the article
http://www.fordmuscle.com/archives/2002/03/coldair/index2.shtml
" It is pretty conclusive that the aftermarket conical filter, relocated to the fenderwell, offers absolutely no performance advantage over the stock air box fitted with a clean K&N panel filter.
Both the stock air-box and the Moroso kit pick up air from the same source -the right fenderwell. So the quality of air entering the engine is not changing.
In the long run, the conical fenderwell elements may even prove to hinder power due to the accelerated rate at which they get dirty and clogged with dirt kicked up under the fender."
"Other than space savings, we found no gains in performance from the fenderwell type air filter system."
To find the silecer, remove the air hose from the airbox, remove the top cover, unbolt and remove the bottom of the box, and you will see a black tube sticking out of the fender well, there may be bolts holding it in, just reach under the fender and twist it out.
In addition to gaining 1-2HP you will also have a nice roar coming from the intake that will be very noticible if you have stock mufflers.
Lots of cars have these, and removing them can help end the hairdryer sound common with toyota trucks