I recently got the PS9 ecu from an auto EX sedan and the intake manifold as well. now what Im curious is, since it is an automatic so you cant chose when to shift, will this swap negatively affect gas mileage? What I mean is, the EX and Si had shorter geared transmissions so will the ECU be telling my LX transmission to shift at different rpms than the stock ecu does, in turn negatively affecting the gas mileage? I just bought this sedan yesterday for a daily driver that gets good gas mileage.

 

As far as I know the only thing the obd0 ecus control as far as auto trannys goes is the torque converter lock up and that will happen at the same time on any trans ie in overdrive with low load.

 

thanks that makes 100% sense now that I remember the only wire going to the transmission is the torque converter lockup solenoid wire