So heres the tip... every now and then and after every time the air cleaner is changed clean the mass air flow sensor !!!!
I did it and well the power was right back up there, fuel economy droped 2L per 100km back to where it should be. The egts are still a bit high for me though but thats another issue.
Its easy to do just grab a can of Mass Airflow Sensor cleaner from super cheap etc some people use other sprays but these can damage the wires so ues the right stuff. Its that common crc make a specific product to do it. It even says on the can "better fuel economy and 4-10hp at the wheels, use after every air cleaner change"
Next find the mass air flow sensor just after the air cleaner and undo the 2 screws.
http://i651.photobucket.com/albums/uu240/droooos/P6230062.jpg
Remove the electrical connector and remove the sensor. You will see 2 wires with a little bulb on the end. In layman terms (My speak
) These wires heat up and the cooling effect of the air passing over them tells the computer how much air is entering the engine and adjusts fuel to suit. So when these wires get dirty with silicone, air filter particles etc (and they can be very dirty but look clean to the naked eye) they have to heat up more to get to the same temp so the ecu thinks there is more air going in and dumps more fuel in than is actualy required.
Make sure not to touch the wires with the spray nozle or fingers etc and do not drop the sensor as they are very sensitive !!!!!
Give it 10-15 good sprays then after it has dried replace the sensor, becareful of the o-ring as mine stretched on removal and had to be careful to get it to seat back in properly.
Now you done and away you go !!!!
Full power is back and better fuel econoomy. This will work with both petrol and diesel models.
, hafta give it a go though. I wonder how different the spray is from CRC contact cleaner, does it dry instantly?
but it cant hurt the economy.. 
