Check your brake fluid and the thickness of your brake pads at all four wheels. My Contour was doing the same thing. Eventually it got to the point when the light was on almost constantly and not just under accel. Turns out my rear pads were so thin that a larger than normal amount of brake fluid was required to squeeze the calipers together, causing the brake light to come on.
You may also have a slightly sticky ebrake or a loose connection down there somewhere. I'd say the odds of this being related to your intake removal are pretty slim...that is unless you somehow smacked the master cylinder while yanking that mass of aluminum out of there!
------------------
Chris Smith
SVT/SHO Society
Taurus SHO Representative
http://svt.sho.tripod.com
89 SHO MTX Light Titanium 122k, Mi. License
1ST SHO, Konig Reign 16 x 7.5 rims, Kuhmo 225/50VR 16's, fender airbox removed, 91+ badges, CincySHO police grill, Covercraft hood protector, silver underhood trim, Pilot driving lamps, Sony Xplod deck, Performance Plus reinforced front mount, Performance Plus y-pipe, Dynomax Magnum bullet race mufflers w/3.5 stainless tips, Eibach springs, KYB struts, MOOG control arms, Royal Purple synthetic lubricants, custom "long throw" shifter, fresh paint, Jolly Roger insignias, trophy winning and MANY MANY mods to come!
95 SHO MTX Silver Frost 92k SOLD 4.14.01 but not forgotton!
96 Contour SE ATX V6 Midnight Red 90k, custom grill & badging, otherwise stock & under warranty