Any thoughts on the ECM no start issue?
the ECM needs to match the wiring in the car.
if it does not the computer will not talk to the engine.
you do NOT need to swap the ECU when doing the ej25 to ej22 swap.
there is a work around for the EGR code ,
but you will need an EGR intake manifold,
and do the work around.
the car will run fine with the EGR code as is,
but it may not pass inspection,
and it will be harder to sell.
a little research could have prevented this.