CM2250 Poor fuel mileage

[stevegrutz]

I ran into a truck that was tuned by rr. It was getting horrible fuel mileage, still drove fine but had a hunting kind of rough hi idle. After various tests and data logging i realized the turbo speed rpm was 0 while running. Found a broken wire for the turbo speed sensor, and now the truck is running great again. It was also a cm2250 and it threw 0 fault codes for the problem.