Can I put a d16y5 engine in an EX with the EX ECU?

[Rubio1381]

Can I put a d16y5 engine in an EX with the ex ECU? What could happen if i did? Is it possible until i get a y5 ecu.

 

[Mr.Baker]

Get the correct ECU.
The Hx has an EGR valve which the Ex doesn't have. It may not run correctly.
They have different fuel maps and are designed for very different applications
If memory serves me, VTEC-E activates around 3000 rpm, the Y8 VTEC activates at around 5000.