Chugging When I Decelerate...
About my truck: '08 F550 4x4, 32k miles, SCT Livewire, DPF delete. I get this "chugging" when I decelerate on the highway, mainly when going downhill. Seems to be more prevalent when it's colder out. This morning it seems worse than ever (24 degrees F outside air temp). Just did a service (oil, both fuels, and air) about 4k miles ago. When my foot is fully off the pedal it won't do it, only when slight pressure is put on the throttle (about 1/4"). As soon as I give it more fuel it clears up. No smoke (black or white) when this happens and no codes. Any ideas???