For me the ECU rattle was a low pitched drumming that happened in a narrow RPM band just barely above idle. It was easily fixed but thus doesn't sound like your issue.
I had another loud wide-band rattle (more of a loud buzz) that lasted until I rolled off the throttle at cruising speed. It was most active around 1700rpm under load. Try giving your front fenders a gentle thump below the windshield pillar.
If you get a loud rattle seemingly from the top of the wheel arch, pull the wheel and the wheel well liner. You will see a plastic support between the fender and truck structure centered at the top of the arch. The support is bonded to the fender with noise damping foam adhesive.
The issue is that the inside surface is attached to the structure with a couple hard plastic expanding nubs. Don't try to remove anything but work a little construction adhesive or RTV into the crevice between the structure and the plastic support. Do this near the top and bottom attach points.
Reinstall the liner, wait for the adhesive to dry and you'll have a nice solid non-rattling fender. I did both sides and my truck is quieter than it's ever been.
There is some more detail in a "Rattle" thread in the diesel forum. I included a pic from the top side but this is easiest to reach from bottom with the well liner removed.
In a bind in the snow trying to get out , it sucks too it's all or nothing and I didn't like that, I tried 2 pedaling it and spooling up the turbo, but it's not great in this little 4 banger.lol
anyone experiencing at red light take off if you punch it a vibration or rattle before the turbo spools up? and only then does it happen, im wondering if the turbo has an issue or its that electrical box guys on here are saying it needs to be remounted with rubber behind it. But it isnt at idle. Just when i mash on the throttle from take off, just till the truck gets moving then its gone. Its like the turbo is having trouble spooling up with the load before it gets rolling. But im not ruling out other things touching, this is just what it feels like. Any info would be greatly appreciated.