There is about 2 lbs difference across the intercooler, no leaks, and just a slight wine at the exhaust and no codes. The part day that it did run properly the engine didn't clatter and was quietier had pulling power right across the throttle band. 61 diesel engines over the years have taught me how an engine sounds and runs. When I was ripping and pushing frozen clay the one time with the D-7XL was a good thing that it ran the way it did to breakup the lease and NOT the way mine does. The little Kenworth towing the 420D backhoe this last summer has more get up and go then mine does that was about 20,000 lbs. Can you explain that please. The other summer I had a lot of trouble getting ahead of a gas 3/4 ton Chev towing a 20' fifth wheel?????????? It has a little more power than my 86 Toyota pickup. If I can't get a run at something to pass it than I can't NO IT NEVER HAS RUN THE WAY A DIESEL SHOULD. Gutless!!!!!!!