Something I like to know, Cats are better than detroits or Mercedes. I think OD doesn't know how to set them up to run right, thats why you are getting all the problems with them... If they are going to replace to the Cats, with a choice to Detroit or Mercedes, they better choose Detroit. Mercedes isn't that good of a motor-plus just the name means expensive repair bill. I would choose the cummins isx over the two choices.:tapedshut: