they do make these chip type things that they cal performance modules and what they do is plug into ur o2 sensor in the intake and basically make it suck it in more air, i've tried it in my Cherokee an it actually did show some improvement.
just go to ebay and type it in and it should show a bunch of results, just there no point in buying a really expensive one there all basiclly the same, just look for lifetime warranties and other little "perks" on the ebay page.
if thats what u were looking for.