94 olds Delta 88 LSS

My wife drove my car the other day, and all of a sudden it started running very rough. Ive got it home now, if you barley step into the gas it runs fine, but for normal driving it feels and sounds like a fouled spark plug. I checked all the plugs but they r all fine. And it does not smell right either while driving it. Any suggestions would be helpful. Thank you. I checked coils and wires, have good spark, checked egr, maf sensor, fuel filter and all r good. What next, please respond