TucsonAZ

There was a prior post long ago that had a remark made in response to a separate post that indicated "i will let you guys know how it works out." The secondary response simply said "famous last words."
So here is my semi long but good informational post:
I own a 2004 F150 Lariat. I am a real estate appraiser, and as a result I put a lot of miles on vehicles.
In March of 2014 (truck has 183K miles) I was out in the desert shooting with a buddy driving through washes and the truck got stuck in the sand. During the process of digging out the truck the engine went into fail safe mode for the first time ever. After turning the truck off, it restarted just fine and we were on our way. Since that episode, I had no other problems until about June when the temperature started becoming over 100 on a daily basis. At first the truck would go into fail safe mode when I was at a stop light and maybe once or twice a week. I just dealt with it. In July, when its really hot here in Arizona, this was happening on a daily basis. I would have approx. 20 min drive time and the truck would go into fail safe mode whether I was doing 75 on the highway or 25 in a neighborhood. Just before the truck would go into fail safe mode, it would behave like an older truck with a manual fuel pump getting vapor locked. I would have to have the hood open and let the truck sit for about 30 min each time before the truck would restart.
The local shop told me the codes were P2111 and P2112 and I needed to replace the throttle body. I removed the throttle body and found that the butter fly was operating just fine so I didn't believe it. I replaced the position sensor, and still had problems. I replaced the throttle body motor, and still had problems. Three shops later, I had new: fuel filter; mass air flow sensor; coils; fuel pump module; fuel pump; the entire throttle body(with new sensor and motor again) as I was told there are two different metals in the throttle body and one was expanding causing the butter fly to stick; and all new rubber lines going into the valve covers and returns. Oddly enough, one mechanic noticed my brake fluid was leaking into the booster. The booster was pumped out finding almost 12oz of fluid in there. It was thought maybe the fluid was ending up in the engine and stalling it out. After a new master cylinder and thorough cleaning, still no change.
Still with no luck, I started reading copious amounts of threads throughout any forum I could find. I found information about the condensation from the AC lines shorting out wires, wire harness having shorts, etc. Well, I thoroughly went through each of the three main wire harness bundles coming out of the computer and found nothing that indicated a bad wire. This took over a week of going through them in the evenings one by one.
One Saturday, I broke down in front of an old Texaco station which had a tiny little mom and pop style garage attached. An old timer came out and was asking a bunch of questions. He simply said, sounds like your computer has a bad capacitor or diode. After rolling my eyes and breaking down on a regular basis with the thoughts of driving the truck off the mountain side to collect the insurance, i decided to research the computers. I ordered one from NY somewhere and the price was under three hundred and included a new set of keys. I ordered it, installed it and went through the set up process after having the new keys cut.
After all this bullsh**, the computer replacement fixed the fail safe issue. Apparently, don't discount the small local shops just because they don't have elaborate auto shops with neon signs, multiple bays, fancy equipment, and fill your mail box with coupons. I did not have one single person ever suggest the computer might be the issue.
It has now been three months with no issues. I will say though, the truck has a renewed throttle response and seemly increased horse power coming from this 5.4L engine.

I truly hope this helps someone out there!