I have a Hypertech OBD2 flash programmer/reader/scanner,
$349 from Mancini Racing IIRC
for timing changes for 87, 89, 91 octane fuels
it's also a scanner,
clears & reads trouble codes,
tire size changes,
top speed & rpm limiter etc.,
version for my 99 Dakota SLT 4x4 5.2ltr Magnum
they are/were Vin # specific/brand model specific, probably back in 2001-2002-ish
I think they have readers & scanners, flash tuners now, that aren't Vin # specific now too
not specific to models or brands either, don't quote me, I haven't kept up on that stuff much
not sure which are the best now,
maybe a tech guy/mechanic still in the field could give a better assessment,
mine works fine for my truck only
I had a Snap-On OBD2 reader scanner {it's not a tuner/flash programmer} a while ago too,
I can't remember which model {pricey thou}
it's really outdated, I gave it to my nephew for his stuff...
sorry not much help here