1991 240sx: are canadian and usa computers intechangeable?

[vancouverbc]

Mine has a big 24 on it. I tried using an american computer with a 28 on it and it ran well for a few minutes but then I could not get it to start. The ignition coil was very hot. I switched between the canadian and usa computer a couple of times and only the canadian computer works. I also got a code 21 which is ignition signal circuit problem with american computer.

[RCG_Savage]

Is yours automatic on manual? also why are you trying to change ECUs?

[vancouverbc]

both computers are manual. I failed emissions so I was seeing if the computer was the problem. Last year , I also failed emissions and it was the computer. My O2 sensor has a high voltage at idle. Not sure if this is normal. ie .9 volts which is rich