The intake doesn't necessarily have to be removed from the truck. You would have to loosen all the bolts holding it down so that you could lift it enough to get the egr cooler out of there and the egr cooler delete in there. Personally, I think it is easier to get it out of the way, plus while the intake is off, you can clean the pounds of soot out of it.
First, check out this PDF file (click me
). It shows the three different high pressure oil systems used on this engine. Your version is that last one down on the document.
The STC fitting connects the HPOP (high pressure oil pump) to the branch tube (on 05-up engines). The branch tube splits the oil delivery between either side of the engine.
The standpipes deliver the oil from the branch tube up to the oil rails.
The dummy plugs are used on the oil rail itself. The oil rails are exactly the same and used on both sides of the engine. To accomplish that, there are holes machined into the oil rails that are not used, depending on what side of the engine it is installed on. To block those holes, dummy plugs are used.
The weaknesses of these parts:
The STC fitting is much the same design of an air-line that you would see in any garage. The problem is that, if you have ever been near an old fitting on an air-line, you can hear it hissing. The internal parts wear out over time. The same thing happens on the STC fitting, but it leaks high pressure oil. This leak makes it difficult for the HPOP to keep up with demand and performance suffers. Once the leak gets worse, it may not start when the oil is hot. Left ignored, it may not start at all. The leak just gets worse and doesn't go away. The fitting can also just explode internally. You could be running down the road one second, and the next, your engine shuts down and you are not going anywhere.
The standpipes have a few o-rings on them that can also wear over time. Failure of those would present much the same symptoms when the truck is hot.
The dummy plugs also have an o-ring on them that could wear out over time. Same symptoms.
The standpipes and dummy plugs can be replaced by pulling the valve covers off. They are installed through the oil rails.
Both the standpipes and dummy plugs have been updated many many times over the years. Each time they got just a little better.
The STC fitting requires turbo removal, IPR valve removal, HPOP cover removal, HPOP removal. Then you swap out the STC fitting for its replacement (a straight fitting) and reassemble.