94 buick century help

i have a 94 buick century runs real rough and smells of raw fuel from exhaust.i was told by mechanic who checked codes to replace egr valve and computer i did also plugs. it did not change still runs the same . also it is the 4 cylinder engine. any ideas?

Welcome to AF, is this a misfire, if you pull the plugs are they wet, one or all? What codes?

i just pulled plugs after running they are not wet but all carbon fouled. does this mean rich mixture. it smells bad of raw fuel when running could it be bad wires or coil pack. it was running a little better before fouling plugs

i would clean mass air flow sensor with eletronic cleaner. also check o2 sensor that will dirty plugs fast.