Thanks for the above guys. Cleaned the maf and changed plugs, oil, air and fuel filters. Hadn't thought about looking at the live-feed read-outs on INPA - will give that a whirl. Car drives really nicely - but fuel consumption doesn't seem to improve from 13mpg (I know it's a thirsty beast - and it's not a shock as such - but it never seems to get above 13mpg even when driving very sensibly - so might be over fuelling a bit). Helpful advice from everyone - so thanks. Will check some live feed on INPA and see how it is.