The proper way for a real mechanic to troubleshoot this is with a simple multimeter to track down whatever is drawing current..
As far as I can tell the issue here is your expectations on the quality of service from the dealers your taking it to... Its just my opinion but I dont feel these...
That was on a long mostly highway trip though.. I only average about 19 in the city in the warmer months... I used to get like 23 in the city. Huge difference the drag from the lift and the gear ratio change from the larger wheels made.
Also your 33s are likely heavy 10ply tires.. im using the...
I was just offering an answer to your question on what you can do other than taking it to another dealer..
You can try an independent shop I guess but I the useless warranty wont help there either.. Or you can pick up a multimeter and look for the source of the current draw since you seem to...
I absolutely corrected the speedo. Not sure where I eluded I didnt.
Raising the truck over 5" in the front and the oversized tires killed my mpg.. even going back to the exact same type of nitto terra 4 ply tire (other than being larger 34" in diameter) only recovered 1 mpg vs 10 ply. the truck...
I wish I knew what tune is on my truck... no way to tell but Its been great! even lifted with 34's I got 25.4mpg on a 1300mile round trip to obx a month ago. When it was lowered 2/4" from stock with 31's I got 34mpg highway! I regret changing that.
cant you just unplug the radio connector? I mean I upgraded my 2015 from the dumb radio to the 8.4 model and dash cluster I got from a wrecked 2017 but the truck worked fine with the stock plain jane radio and cheaper low feature dash cluster so...
I got a stock mid model radio and dash cluster...
I had the error when installing one of the aluminum trans pans.. the linkage arm in the trans was rubbing on the inside of the new trans pan. in my case I found I just overtorqued the pan and the issue cleared up when I loosened and retorqued.
lubricate the universal joint in the steering shaft between the box and column... that was the source of my issue 2 years ago..I bought a replacement but after greasing the needle bearing with lithium grease spray I havent had the issue return.
EDIT* sorry I need to be more patient before replying.
After seeing mopars markup on the saleri pump I found them new from selari on ebay for $268 but you need to transfer the rear coverplate from the old pump... I decided instead to just buy a GMB pump from rock auto for like $100 and watched the youtube video on replacement.. did it in my driveway...
You can buy a rebuilt or junk yard motor but most of the ecodiesels in the junkyard died from the same engine flaw so... this is one way to get rid of the gen 2 ecodiesels out there..
Wow thats a fast turn around! I see others report waiting upto 4 months while they are getting an engine replaced. (Since they are typically failing faster than they are selling replacements lately)