Ecu issue

[scooberblue]

Hi everyone.
I have a slight problem at the minute that hopefully
Someone can help me with.

Right problem is a have an ecu that the seller swears
Blind was removed from a my99 impreza but when I
Plug it into my car it won't start an just flashes the abs
Light irraticly. The code on the ecu is F6 wich is a forester
Ecu but he swears blind it's a impreza ecu an the case has been
Changed. In fairness to him there is no locktight stuff on any
Of the screws. So. If he is being honest the only thing I
Can think of is maybe it came out of an import if so what pins
Would I have to change to make it fire in a my99 uk?

Many thankies any help would be appreciated

[asperformance]

cant recall pin numbers off hand but the cam/crank are transposed JDM to UK