Okay, I've painfully read through this entire thread and this type of crab sessions I usually avoid. However, a few observations:
How steep is this driveway/hill? I don't see mention of it in this thread, but somewhere there's a serious lack of a test of reasonableness.
I didn't note any attempt to go though the state lemon law. If so, why?
How has been determined to be a 'high idle' problem? None of my 5.7s first start, cold idle went much over 1600 RPM, and usually drops to 1000 in less than 3 minutes. I still have to apply the gas pedal to get out of my driveway, and that's a little downhill.
No manufacturer, FCA, GM, Ford, any of them, can alter the previous certified engine program without recertification and federal approval. And a dealer who wants to keep his franchise can't legally do it, either. FCA will only issue a modification if the issue is proven to violate current emissions standards, or driveability issues affecting a broad population of vehicles.
By now I'd cut this person a check and buy the vehicle back if I were FCA. It's possible that any design could produce a problem in a one-off situation. Dealing with that could ultimately cost more than buying it back. There doesn't seem to be any incentive to maintain the relationship, and expecting to talk to everybody up the chain is just not realistic.
Lastly, and not to be offensive, but the quality of communication leaves much to be desired, especially for a person that indicates they are an engineer. I have a sense that it could be part of the problem.
Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 17 July 2018. Now at: 029914 miles.
