I had previously posted a topic in the drivetrain area before the towing forum was added. I was having trouble with my Banks Exhaust Brake. It seems that it was sticking and so the back pressure was causing the truck to lose power. Banks has acknowledged a machining problem and is sending out a new unit. I asked them about a quieter muffler as I had also purchased their 4" exhaust and they are sending me a new muffler. It is nice to know that they provide service to their customers.