I've read reports here of better running (fuel mileage too maybe?) with the off road device that fools the ecm over just forgetting to plug the maf back in after off roading

Reading the Bosch diesel handbook for the older computer systems like used on older TDI's when a sensor goes bad the ecm uses other sensors and falls back on a backup "plan B" to keep the engine operable. I suspect the same is true on our crd's with newer Bosch ecm's

If they just needed the maf for egr I think they would have left it off and controlled egr some other way and it's hard to tell what all is being changed
