Originally Posted by
pani_k
Maybe something like the VSS if it seems fine going backwards? Have you really tried booting it backwards to see if it totally fine when reversing?
Also you mention it was low on fuel so I would think about looking at changing the fuel filter (relatively cheap about £12 for Ford although since I last bought one might be about £32 now lol). Blocked cat would also caused above issues if running lean but strange as to why it won't do it when reversing...
Does it rev clean when in neutral?
I second the blocked fuel filter personally although that doesn't andwer why diagnostics pointed to coil. Its worth checking the plugs are in good nick and set to the right gaps, colour will also indicate if its running rich etc. If the car is more than 10 years old and on original leads it would be worth changing them too as they will be passed their best.