I Think This is a Big Problem
The computer strategy for a DBW system is based on the electronic control of the throttle opening and the computer adjusts it based on engine load and pedal angle. Without the pedal angle the computer won't know what to do!
Its been a while since I played with this stuff but don't think there is any easy way to do this as I understand the pin-outs on the earlier processors are different.
Actually DBW systems tend to really improve fuel economy and performance. What are you looking for?