If none of that other stuff works, your EGR valve may be stuck open. That would cause rough idle because it's supposed to be closed at idle.
'99 Sport TropicGreen,Duratec, SVT exhaust, Brembo rotors, Ceramic pads, K&N filters(oil & air), Alpine CDM7874, Polk DB570 speakers front and rear. Fog light mod. 50% Formula One tint.
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