406oc.co.uk

I want to replace the standard Peugeot spark plugs in my 1996 2 Ltr 16v petrol 406,to see if it resolves a problem I have. Apart from an erratic tickover problem which is currently lurking on the forum under another thread, my car has started to "bog" or "miss" at high speed,and I was wondering if it could be the plugs breaking down.Has anyone got any opinions on the Bosch super4 plugs as opposed to the normal single electrode type.Which are the best suited to my 406 please. My car has covered 155,000 miles and still has the original Ht leads,and would like to know when they should be replaced.

I have used the super 4's before and to be honest they made no difference at all (maybe psychological? )
I'd replace the leads with the plugs as a matter of course, they're not dear.

Changed mine 4 weeks ago from 2 electrodes to 1electrode plugs car runs better but not sure if it was just that it needed new plugs .I think I read on the forum that our engines dont like multiple electrodes .Maybe someone could confirm that