nitrates

Cats don't use a filter.

 

What coolant originally came with it?

 

A water filter is an option on every engine, and something that should be standard equipment.
The stock coolant in most trucks is Power-cool, a Nalcool, Dexcool product. The optional coolant is Power-cool Plus a noat coolant. Both are great.

 

Water canisters are not needed with the newer coolant types, that's why you don't see them any more.

 

These colors are not really written in stone. I had my Detroit factory filled with their PowerCool Plus ELC... nitrite free per DD specs, and it is red in color. The Rotella Ultra ELC (nitrite free version of their ELC) is yellow, but I think that is to contrast it to their red standard ELC. The Final Charge ELC stuff you see at the truck stops is nitrite free per their spec information on their website. It is red also.