misfire

i have a 92 yota with the 22re...it was running fine then all of a sudden if starts missing,a little here ,a little there,not but...but real annoying,now its getting worse,the fumes that are seeping into the cab burns the eyes and really stinks,it also does it at idle as well as at highway speeds..if anyone has a clue i would much like your input(the check engine light is not on)