Starts and runs/idles rough until you accellerate some the it smooths out and runs like it should. The exhaust smells "gassy" like it is running rich. NO codes or SES. Could it possibly be the temp sensor for the ECM - giving it a false reading and the computer is feeding it more gas than it needs? Seems to be doing it more/worse the colder it gets. I don't believe it is ignition in nature as I have replaced the cap, rotor, plugs and wires.