The truck needed all those parts as all the electronic sensors were not reading when I hooked top my scan tool and read the live data. Those spark plugs I put in when I first got the truck. I know for a fact the truck was well maintained previously, however it was sitting for 5 years prior to my purchase. If you look at my meet Roxy thread you can see a picture when I took off my valve covers off and see that there was NO sludge. Indicting regular oil changes. This was a fleet vehicle prior so it went in every couple of months for inspection, oil changes, etc.Deposits like that at 7k aren't exactly normal BUT could be in your case. Not knowing how the engine was treated and maintained in the past could be indicative of carbon deposits being burnt up since you've put the effort into making the truck happy with new parts. Taking into consideration the evap issue you're having, and not having a quality part, in theory could be your exact issue. Since the new parts fixed it for a minute, get a good one and see what happens after that.
Here's what I'd do before changing parts. Give it the ol' Italian tune-up. Put it to the floor. Do it for Dale. Get that old gunk burnt out. Sometimes it's that simple. A lot of us tend to think more than we should. Being a former European car tech and dealing with those difficulties, sometimes the simple things go overlooked because you know too much. The simple things become complicated because what's actually just a bad coil pack makes your brain think capacitors in the ecm.
Schurkey, what oil and filters do you use? How did your tests come back? We all know modern oil can do it and the filter is the failure point, which you're obviously smart enough to abide by. I'm sure we've all speculated trying it but I surely don't have the stuff between my legs to actually try it!
OB1214