So I changed my existing NRK ones to Bosch Super 4....the old ones did 7000 miles and have black deposits around them. From what I can tell, this means the engine is running too richly? Is this right?

Any solutions to this?

So I changed my existing NRK ones to Bosch Super 4....the old ones did 7000 miles and have black deposits around them. From what I can tell, this means the engine is running too richly? Is this right?

Any solutions to this?

Indeed it does mean it's running too rich.

However... That could now be sorted if your lambdas and map are sorted...

It's worth keeping an eye on them - you obviously can't tell whether the remedial work you've done has improved matters yet.

Thanks for clarifying. After giving the MAP a thorough clean, I don't think there's much I can do with it. Replacing those vacuum hoses might help I guess....the ends were very loose. Air leak, perhaps? As for the lambda....need to start looking for a cheap replacement without going to the dealer. Although the next task at hand is to fit the Whiteline RARB I treated myself to :p

I've read mixed things about cleaning spark plugs....a bit of carb cleaner can't hurt, can it? And a gentle brush? Not a wire one though...that might shift the electrodes....

I've always used decent sandpaper and carb cleaner, then re-spaced them before putting back in.