No sealant is to be used, otherwise the gasket will squeeze out. Try to use a very accurate torque wrench, I made a copy of the manual and followed the torque sequence exactly.
Also you should have new exhaust donuts/rings as you will have to remove the lower pipe. I also stripped some exhaust fasteners too, the lock nuts are hard to find and even harder to get off after 10+ years.
If you are going to use an impact wrench on the exhaust nuts, make sure you remove the o2 sensor first, apparently the vibrations could damage it. The inside of the pan will be a little rusty, so you should set aside the day to cleaning and painting the inside of the pan.