Originally Posted by Mate2011RT
It is not truly necessary or it would have been added when the vehicle was designed. Could it be a good idea? yes. Looking at the amount of oil I get out of mine, I prefer to have it rather than recirculating oil into the intake, but it was designed without it, and it is your truck; do what you wish with it.
I am pretty sure the only reason catch cans are not added by the manufacturer, is because it becomes a maintenance item easily overlooked by the average car buyer and could pose a real problem if not regularly drained. Manufacturer's have in general tried to reduce and/or stretch out maintenance requirements.