Reversing a bad (non cummins) tune

[mikkhh]

Reflash by tuning tools full ecm read?

Most likely somebody blanked most if not all fault codes. Not sure what ecm but good test is to pull ecm plugs and then crank engine. See how many fault codes you get compared to a good reference. On regular cars that is the first test I do when something has been tuned deman or whatever or at least suspect. If car gets only 7 fault codes that way or even less then it means troubleshooting and or repairs are going to be time consuming unless ecm is flashed to factory programming.

Reflash by dealer? Dealer scan tool reflash may not flash all areas (there are like bootloader area, changeable settings, program code, etc) and sometimes the "tuning" guys rewrite program code etc and other areas that should not be touched at all. Also "tuning" software quite commonly corrupts the file and also writes some no read or specific fimgerprimt all around the file and again can mess up the areas that must not be touched. It is not uncommon for tuning guys to lock ecm for further reprogrammimg attempts.

Are there even factory lenient overseas no acm factory conversions available for those engines? That would be the only way to fix these, but e g r will be kept, that can be lived with. Most likely cans are hollowed out and those trucks would need lots spent on new / used cans? Besides the fact that overhead adjustments have to be done, egr tuneup etc.