Hi i think the part you require is the ignition modular lokated on the o/s bank at the front of the engine,is it a small alloy box with cooling fins? If so mine was brought from my local Nissan dealer in Derby at a cost of around £270,i brought and fitted mine 3 days ago and they had 2 on the shelf of which i took one, now the car runs sweet again.It is easy to fit aswell.I hope this helps.

Thanks mate