940 ECU question

[sbtaylor]

I have had a 1994 Volvo 940 for about 3 years now. It was a turbo, but a previous owner had blown the turbo and dropped a 1992 B230F engine into it. I recently checked the ECU and it is the correct ECU for a 1994 Turbo 940, but should I replace it with an ECU for a non-turbo, such as the 0 280 000-951? Car runs well for its age but mileage is a little low, 15-18 mpg depending on type of driving.