I would take it to some one who knows what they are doing (has dealt with rst's and mfi before) and has a rolling road.

I don't doubt you can set up a standard car with a CO% reader, however anything modified will need the ignition timing changed from stock, best done @ full load with det cans on a RR. The EMFPR is 'adjusted' by the ecu as chaffe says however only to with in certain limits (as far as i know) the actual base fuel pressure is usually adjusted with the EMFPR making its adjustments as needed on top of that. IMO one of the reasons MFI is such a compromise on a modified car.

Good luck!

Rob,