MY forcus has been of the road a while having work done for mot. The battery went flat so I charged it but on refitting found it was knackered. I bought a new one today and fitted it. When you drive it it has a slight misfire and is under powered. There is NO management light on and is displaying a DTC9318. Can anyone help as ive never had any problems with the car so it seems odd it suddenly has developed this miss fire!

Cheers for any help.