Last year I swapped the dash board, steering column and majority of the wiring from an '85 150 into a 79 250 (needed the extra payload, but wanted to keep the comfort). Anyway, just recently (after about 10K with the new setup) the "Emission" light has turned on.

Does anyone know what this warning is referring to? I'm gonna pull the bulb out of the panel one of these days and maybe put a switch for something in it's spot (fog lamps are always cool ) but if it's actually diagnosing something for me I would like to know.