Loss of power while towing...
I have an '05 6.0 with 4" down tube, no cat, or muffler.... While towing our tow hauler yesterday after about an hour it wouldn't go over 10# of boost, or barely get over 50mph downhill and was a real POS for any pull. When this happened in the past, I pulled codes and it said low exhaust back pressure... Well, yesterday when it happened, I ran it for a bit and pulled over, turned the truck off, unplugged the CPU for 30 seconds and I was back on the road and it ran normal.
So my question is, do I need to have my cat to have the necessary back pressure while towing to keep the CPU from "tuning it down?" Any feedback would be appreciated.
Thanks for the help