Land Rover Repair: loss of power, mass air meter, mass air flow meter

Question
Let me start by saying i love my 1996 land rover discovery sd 5 speed. Now my problem, i have a real problem with loss of power going up hill, at 30mph i would have to down shift 1 or 2 gears to make it up. the truck is very well maintained, up to date on all services and fluid changes. Could this be the mass air flow meter?

Answer
I doubt if the problem is as simple as swapping a mass air meter.  I think you should find a shop that has the proper LR test gear, and watch the live data stream as you drive up hill.  I think the data will tell the story; something will be way out of range.  If not, you may have a clogged catalyst or some mechanical issue.  I do not think this will be a "swap a part and be done" problem