All, I have been looking into this as well, I like my 2.5 although bagged by Mazda, it has Ford stamped all over it. I have looked into a Cold air intake but just can't seem to part with the $$$ has any body built one on their own, say out of PVC or other material? If so how difficult was it and would you care to share instructions? I have also heard about cleaning out the air filter box (removing baffels)? One last note, or question, what would be the largest exaust pipe system you would reccomend. And as I think about it has any one ever tried raising the actual intake by say an inch or two (allowing for more air fuel mixture prior to going into combustion? Sorry to ramble, but all these ideas have been on my mind lately. Jason 98 Mazda B2500 38k(All Ford)

"And as I think about it has any one ever tried raising the actual intake by say an inch or two (allowing for more air fuel mixture prior to going into combustion?" They do make products, I'm not sure about for your engine, called Intake manifold spacers which do what you are talking about. Usually runs anywhere from $50-$150 and will yield HP gains of 5-10 hp. . .if you have the hood clearance to install one. Jas and Jen Hark