Does sound like a MAF (mass air flow) issue.
What you need to do is unplug it and see if it improves. The MAF is the matchbox sized box that is attached to the side of the air filter box with 6 or 8 wires attached to it with a multi plug.
Unplug it and take it for a drive and see if it is any better. You may still notice some slight loss in performance as the engine will be in 'limp home mode', and there may be an engine management light on on the dash after you do this.
If it is noticeably better then you have found your problem. All you need to do then is plug it back in then disconnect the battery for half an hour again to reset the engine management light.
Rich
