Possible engine or gearbox fault

Hey folks,
Was just wondering if I could pick your brains on a auto k11 1.0 x reg possible auto gearbox or engine fault?
The fault is "Lacks power when you press hard on the accelerator, fine if you drive on light throttle."

I havn't seen the car myself, as it is on ebay auction and ends in 3 days. Low mileage and fully serviced seems to be in good condition.

It is a coil pack version.
Usually, with these it seems to be a fault like this, it has been known to be around the throttle body or a sensor.
Though as it is an auto, I was was wondering if this could be put down to something to do with being automatic. i have heard some micro switches or something like that can play up.

Any input would much appreciated and thanks in advance for any suggestions.
The coilpack auto gearbox doesnt use the powder clutch. The MAF's are quite a issue on the coilpack Micra's. Common fault is lacks power. Mainly noticeable from 3000-3500 rpm and up.