Hello there!
I have stucked into a problem with my ECU. This one started with 1st oxygen sensor as I bought my ride with already lighten 'check engine' lamp and error was being . I changed sensors, but nothing has changed. When I extracted ECU I found out that oxygen sensor's microchip didn't work. Then I bought another ECU from Japanese Civic ES2. I changed microchips, but nothing has changed again. Due to the fact that wires works properly I came up with idea that all the trouble is in either CPU, or in ECU in general. Now my EM2 works on 37820-PLR-L55. When I was surfing eBay I checked out that this one fits vehicles up to 2003. My ride was manufactured in 2004, restyle. Looking for clear and professional advice! Cheers.

 

These cars have immobilizer systems. You're not going to be able to swap the ECU and get the engine to fire without pairing the Immobilizer system first.