This last month I have been having to drive all over CA, I've pretty much put about 4,000 mi on my truck in the month. All highway miles with no towing. I had to drive up to June lake(9,000+ft elevation) for a bachelor party fishing trip. On my way home ~500mi into the trip I got to sea level and my check engine light came on. I pulled over cycled the ignition to read the codes through the odometer. They were:
P doNe
P PCU
P 1693
ECU
P 00237

After reading them the light went off. When I got home I had to run to the store and on my way there I got a dead pedal. 5 mi down the road it went away. I figured my VP44 was on its way out (truck has 180,000min on it and to my knowledge the VP44 has never been replaced.) My fuel press gauge when out so I couldn't check for proper pressure. So I drove it the next day to the nearest service station ~60mi away with no problems. After checking it they couldn't diagnose the problem. They said my lifter pump and VP 44 were fine and that the code corresponded with the boost sensor detecting and over boost and the truck was over fueled? The guy drove it said it ran fine and couldn't find a problem and that the sensor did not need replacing, and to keep driving it and if it happened again to bring it in. Does this sound like a proper diagnosis? Any thoughts suggestions? The last thing I want to do is drive up to Napa(300mi) this weekend and have my VP44 go out on me. The only thing that I did that was out of the norm was while I was at June lake the guys egged me on to turn on the chip and see what the truck could do. So I threw it on and gassed it for for like .25 miles. That's it. Any help would be greatly appreciated. Thanks.

 

could be your apps is going out