Since your BP seems fine so I won't worry much about going over your daily sodium intake once in a while, but look at your 'Fitday' at the end of the week, divide by 7 and see if you're far over 2400 daily. If you find you're retaining water & slowing your weight loss, you might consider switching off sausages, rinsing your tuna, any other canned foods (this is what I do, since my BP used to be high).
You can easily make your own low-sodium sausage from ground pork/veal/lamb or any other meat you like + spices (I like 1 part each fennel seed & crushed red pepper to 1/2 part sage & rosemary). Packing the meat into casings is a whole 'nother thing, so I just make patties or 'kebab', or just eat it well cooked & crumbled. Luck to ya!