Is it clicking when you try to start? I had an issue with mine once where it wouldnt start; there was a click when you tried (solenoid would click) but it would not turn over. I ended up calling roadside to tow from my driveway but before they could arrive I went out to record what it was doing...
Mine has a really odd smell when its Cold, I assume its the DEF because my dad's Duramax and brother inlaw's powerstroke (both pre DEF) dont smell like it at all. I would not use the word "sweet", im more with you on "offensive and stinky".
Try going back to the store where you bought the stuff and ask them to reprint receipts. If you know the date and what you bought they can normally look it up in the system. I had to do this for the same issue as you; my truck is in for a motor and they wanted my receipts. I couldnt find 2 so I...
So this sounds almost word for word what happened to me this weekend. Headed out hunting, ~277km drive, all highway. I made it to about 273km no issues, running great. Came to a hill and on the way down (cruise set to 90km/h) it downshifted, RPM came up to about 2300 and bottom of the hill it...