I first noticed the problem traveling up a slight grade. I had Tow-Haul on, I was in OD (or the highest gear), the RPM's were about 1900, I was traveling about 60-63 MPH, and there was about 18 psi on the Turbo Boost.

As I pushed down easy on the accelerator, I heard a coughing or missing noise, felt a slight loss of power, and the turbo boost needle flucuated. Once the engine down-shifted, it went away. I could recreate it on any slight grade, get into overdrive, give it slight easy gas (as much as it would take before causing it to downshift). It almost seemed as it was choking on the fuel, before down shifting. The noise almost seemed metalic.

This only happens while towing.

 

Welcome to the site....please read the Guidelines....enjoy FTE

 

My bet is the turbo. I towed 6000 lb horse trailer up some steep Ozark hills at speeds up to 70 mph without any malfunction like you mention and then last night brought my camper that weighs more home on the same road with no problems. The new brake controller works like a dream and is very "smart" - it told me there was a bad connection on the camper.