Lumpy at low revs

Sorry Me again.Wifes 1.8 zetec 1996 escort has an annoying missfire at low reves.I have gave her a good service (the car that is,I know what your thinking!!) plugs, new leads, ect & put some injector cleaner in the tank but still no joy. I have toyed with the idea of changing the coil pac but above 2000 revs the car is fine. any suggestions??

Give the EGR valve a tap while its idling. It sounds like the EGR Valve isn't fully closing, possibly because of carbon build-up on the seat..

will give it a go thanks for reply