odd missfire

[mooser]

hey recently noticed that when my cars cold it missfires when the revs are below 2500 rpm and its down on power the cars a 172 cup its fine when it warms up but does give the odd miss iv bought service parts plugs filters and a panel filter and am waiting for a coil coming too hope thats a fix for it but if not any ideas

on a side note i think the cats on its way out

cheers in advance

Mickie