Hi Stu, hopefully this will contain enough infformation for you to bin the idea, save your money and do the right thing with regards tuning enhancements.

Phone Devon 4X4 and ask "What's in the box?" It may just be a resistor that fools the fuel fuel rail into thinking it's under-pressurising and as a result gives you the power gain by simply throwing more fuel at the engine. These plug and play boxes have undoubtedly come a long way perhaps but it is something I personally would never consider when there are proven and safe alternatives. They are cheap for a reason, primarily they have not had the expense of time and money in development.



**Edit** Found these that may confirm my theory about just dumping more fuel at the engine.....

http://www.psi-motorsport.com/turbodiesel/powerbox-e.php

https://www.landyzone.co.uk/land-rover/psi-power-box.115301/

Another thread on the same subject albeit not a 2.2.

http://www.defender2.net/forum/topic33150....+power+box

Martin's spin on tuning boxes.....

Martin wrote:

A tuning box can never match a true remap. Tuning boxes fool the ECU and engine into operating different to what each other "thinks" - i.e. it's a box which modifies signals going both ways to trick them.

At its crudest, this is simply a resistor to lower the rail pressure signal to the ECU, so the ECU raises it as it doesn't match its set point. Higher diesel pressure means more diesel injected per firing, but it takes NO account of the other engine parameters required to determine if this is a good idea or not.

These parameters can include but are not limited to fuel temperature, boost pressure, engine temperature, driver driver, inlet air temperature, charge temperature, air flow, gearbox gear, EGR state... [etc]

A remap does increase fuelling, but by altering the maps which are read as a result of looking at all these other parameters FIRST. A tuning box lets the ECU work out where it should be operating, and then just bungs some on top, and lies in return.