I have an 04 F-150 with the 5.4L 3V engine, at 160,000 lost oil pressure to the right cylinder head and phaser. $4500.00 for a reman engine at a local rebuild shop, installed. $5500.00 for same engine, bored 30 over, heads and deck machined,4 year 60k warranty. Biggest issue with these engines is the wrong oil filter. Ford has issued a TSB that states a) change plugs at 60k instead of the original 100k. b) use 5w30 vice 5w20 oil, c) use oil filter with silicon anti-siphon valve. (Motorcraft), and the other is a Cylinder misfire. Coil packs are notorious for breaking down at high revs and heat long before they will at idle. Take it out, open it up and see if it sets the code, goes into "Limp-Home" mode, misfires, sets the check engine light or other symptoms. Run the codes after that and see if you still get a code P0302. My bet is a bad coil pack. Truck has 190k on the clock now, excellent results with the engine build.I intend to run it at least another 100k.
I drive 100 miles a day, getting 17 mpg on the highway, and it is still the most comfortable ride i own.