I had the same exact problem with my car. had random misfire and went away and came back off and on. replaced plugs wires (needed done anyways). checked all the coils. i went through everything. then a lean code came up. checked all vac lines with carb clean. absolutely nothing and still had the random misfire. Started with the carb clean again and sprayed right under the s/c snout. s/c gasket was leaking. replaced it and everything went away. what was weird is that the lean code never came up for a good week or 2 after it all started lol. Not saying thats whats going on with you just thought it was interesting that the random misfire on 6 was the only code it threw lol
