My last 4 trips have been to the west which means that I have to go through the mountains.I have been getting Detroit Diesel codes that my local service center was not sure was a problem.The last trip there were 2 codes(1) Intake Manif Temp E197 (2)Air Inlet Temp Too High E11.On an earlier trip I actually got a reduction in power for 10 seconds or so.My fuel mileage is down about 1/2 MPG and I have a small amount of black smoke when I depress the accelerator slowly.Kevin at Covington Detroit Diesel in Greensboro,NC found that the Charge Air Cooler is cracked and that the crack has grown.Since this part is a Prevost part and not a DD part and Covington is not a Prevost Warranty Center I had to get Prevost to approve the repair which they did in a very professional manner.Brian Joy from Florida and Lindsey from the Volvo office in Greensboro,NC handled the paperwork and Covington ordered the part,there are none in the USA but it will be shipped from Canada.This cooler on the EGR engines looks to be about 200 pounds and is a huge radiator,hopefully this will cure my problem for good.