First, YES, it does make a BIG difference what filters you use on your truck. FORD owns patents on devices that are in the filter housings that MUST be engaged properly for the filter to work as designed...period. NO, those NAPA filters do not engage them properly.
For instance, in the bottom of the oil filter housing, there is a poppet valve. Its purpose is to drain the oil filter housing when you crack open the filter cover. It makes oil changes so much less messier than if it was not there. However, this makes the height of the filter absolutely critical. It must also fit perfectly to engage that poppet valve. The patent on these design features make it a REQUIREMENT that you use Motorcraft filters, and ONLY Motorcraft filters (unless you can find a filter made by Raycor, since they manufacture the filter for Motorcraft). Using any other filter will not engage that valve properly, and what happens is that this valve can stay open. This will effectively open a 1/4inch hole in the oil filter housing that is draining straight to your oil pan. Try clicking
HERE to get the proper filters. You can get either the Motorcraft or the Raycor filters through them at discounted prices.
The fuel filter has other devices on it that must fit the filter as well, and is also patented by FORD, and again, no other filter will work properly.
Oh, before I forget to mention this, you might have to purchase a FORD oil filter cap if those NAPA filters come with their own cap. The NAPA cap will not work with the Motorcraft filters.
That guy at NAPA might have been talking about the fact that under maximum oil flow (a whopping 18.5 gallons per minute by the way), the stock filter will only be filtering about 8.5 gallons per minute, leaving 10 gallons per minute unfiltered. The only way to improve on the filtering of the oil is the separate purchase of a bypass oil filtration system OR by deleting the stock oil cooler and installing the bulletproof diesel oil cooling system. The oil cooling system replaces the stock oil filter with an external oil filter head (and externally mounted oil cooler) and will filter the oil at very close to max flow. ($2300 give or take a few bucks for the system)
The NAPA filter will not filter any more flow than the stock oil filter since the flow is set by the bypass valve in the filter housing.
To the best of my knowledge, a cam sensor won't do this. You will get a cam or a crank sensor code by cranking the engine over for extended periods of time, and that is normal.
My suggestion is to replace your oil filter (at a minimum, preferably your fuel filters as well) with Motorcraft filters. Believe it or not, this problem could be as simple as that.
Your 06 also has the STC fitting, which is WELL known to fail. The fitting is what connects your High Pressure Oil Pump to the rest of the high pressure oil system. STC = Snap-to-connect.
This style fitting is much the same as the fittings you would find on an air line in your garage. The internal parts wear out over time, and that would cause a leak of high pressure oil. You will not see any external signs of a high pressure oil system leak, it is all internal.
The signs of the fitting failing are pretty much what you are describing, but not exactly. Usually as the fitting fails you will have great difficulty restarting the truck when the oil is hot, since hot oil will flow much more freely than cold and the leak would be more prominent.
The failing fitting can cause the engine to just cut right off.
That is why I think it could be a combination of the two. Your STC fitting is probably failing (or other high pressure oil component) and the wrong oil filter.
If you have already had your STC fitting replaced, the other two high pressure oil system components that would cause strange things are the dummy plugs and the stand pipes.
A quick-and-dirty explanation of the high pressure oil system:
Oil flows through the oil cooler
As the oil exits the oil cooler, some of this oil is diverted to a reservoir under the oil cooler.
This reservoir feeds oil to the HPOP. The HPOP pressurizes the oil
The IPR (injection pressure regulator) is screwed into the HPOP and is controlled by the PCM. It is designed to regulate the oil pressure sent into the system by opening/closing, bleeding off pressure to the oil pan.
The oil will then flow through the STC fitting and enter the branch tubes.
The branch tubes split the oil flow into two directions, one line for each side of the engine. The branch tubes pass the oil to the standpipes.
The standpipes deliver the oil to the oil rails. These standpipes have o-rings on them that can fail over time.
Both oil rails are of a common design. To accomplish this there are holes machined into the rails that are used on one side of the engine, and not on the other side. A dummy plug is screwed into those holes. These dummy plugs also have a seal on them that can weaken and leak over time.
Both the standpipes and the dummyplugs have been improved many times over since your engine was manufactured and there is also an STC fitting replacement kit that replaces that style fitting to a straight fitting (which it should have been from the factory).
To replace the standpipes and dummy plugs would require removing the valve covers.
The STC fitting requires the removal of the HPOP.