Is it possible that there's too much oil on that K&N filter?  I've never used a K&N filter myself, but I understand that one potential problem with them is that the oil used on them can foul the MAF sensor.  If the MAF sensor thought there was more air going through it than there really was, then the PCM might dump more fuel in to compensate, which would make the mixture too rich, which could produce black smoke, and perhaps your other symptoms as well.


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Moonlight Blue 1996 Mercury Mystique GS , Zetec engine, ATX.  No mods. (Well, OK, one mod.  Before I got rid of my previous car, a 1994 Tempo, I swapped radios.  I liked the Tempo's radio better.  That counts as a mod, doesn't it?  I also kept one of my Tempo's wheels to use as a spare.  I hate those stupid ?compact? spares that come with modern cars.  Does this count as a mod?  If so, I guess I have two mods.  Replaced burned/melted blower switch and connector on 19 February 2002 with a 1P3T toggle switch from Marvac and a Molex connector from Rat Shack; I guess this now makes three mods.)