All right, I checked my fridge and the pizza sauce we use is:
Enricos All Natural Pizza Sauce.
6 carbs total for 1/4 Cup of sauce.

I buy this at our health food store and we may use 1/2 Cup at a time. The LC pizza crust we use is about 8 inches in diameter, so it doesnt take allot of sauce. There are lower carb pizza sauces out there, but we really like this one.