I'm convinced that some CRD guys here have boost leaks and don't know it like I did. If anything like mine, on the turbo resonator, you won't get any clue that it's leaking. Just bad MPG. Everytime I see a CRD doing 18 around town 20-22 on highway, that's what I think. That's exactly where mine was before I had a diesel performance shop fix it. Dealership said nothing was wrong. With GDE, DPF delete, turbo res delete, I get 30mpg at 55mph. 21-23 around town.