Ive been researching brown gas along with a co worker, the idea is sound, i haven't tried anything yet, but the bonus to it is, everything you do to the car is completely reversible and cant damage the car if the tuning is done correctly. If you want to try it i recommend using an OBD1 Honda civic, mostly cause itll be cheap to pick up and the ECUs from honda have been completely reversed engineered so tuning isnt a matter of a piggy back or a fake O2 sensor.