Has anyone else noticed the black soot above the exhaust on the white trucks? I have a 2010 DC 5.7 with the 18,000 miles. I do have the Toyota chrome tip installed on it and have moved it even further out to see if it would help. I washed truck today and noticed it still has some soot on it, but not as bad. I called the dealership and service manager said they ran rich at start up and that is where it was probably coming from. Any ideas?