Im assuming you already removed the climate control unit, did you also remove the ac compressor, condensor and associated hoses/tubing? How about all the egr/secondary air injection valves, tubing and other associated parts? Im sure you couldnt care less about a check engine light, performance shouldnt be hindered with removal of that crap.
Any extra wiring for things you arent using (ie: power seats/windows, radio, amplifier, etc.) can remove small amounts but it adds up.
Just some thoughts.