After months of the car idling not as it should i.e. It would go from 500rpm to 800rpm then settle at 620 for a bit then repeat it was also impossible to hold onto a rev range under 1000rpm as the needle would bob up and down constantly .. I took off my air intake pipes checking the rubber seal inside them was good and then spray half a can carb cleaner towards the throttle body. Never touched it as I'm aware it's sensitive..
refitted everything and cars now perfect! Not sure if one of the pipes was improperly fitted or the carb cleaner helped but I did notice it dislodged a bit dirt at the front of it..! Either way I'm happy as it's only been a £5 fix.. now taking her out for a full tank of vpower fuel and a wee burst to Glasgow just for the sake of it..

Good for you, I fitted a new Bosch MAF recently and that made quite a difference, and I have recently got over my head gasket scare so I too have been going out on random drives doing my best to rid the planet of fossil fuels so we can get V8 hydrogen cell cars even sooner
I was only messing, and then I found this ....

http://forum.lro.com/viewtopic.php?f=42&t=21425

I had a bad idle on mine too. It would rev to about 1100 in neutral or park then very lumpy between 600-800 in drive.
Replacing the airflow meter solved it for me.