Mazda 3 engine swap

[racerflash@aol.com]

Hi Guys, I'm new to your forum so be gentle.

I'm a long time Mazda owner, RX7 TT, many Miata's, and now a CX9. My son just bought a 2005 3 with a blown 2.3L motor. He found a really great deal on a used motor, but it's a 2.0L from a 2004 3. We are trying to find out if the 2.0 motor will work in the 2.3L car. Blocks are the same and he found out that the Auto Transmission is the same for both motors. We assume that the 2.3L ECU won't work on the 2.0 motor?

Can anyone out there offer any advice? Would we only need to get a new ECU? Would the 2.0L ECU work with all the other electronic stuff in the car (dash, etc)?

He can buy this motor for less than 1/4 the price of a used 2.3L motor.

Any help or ideas would be greatly appreciated!

Thanks,
Flash