i believe your right on it bush, the pilot inj. was changed with the 04's from what i understand. the 03's with the PI were quieter from what i have been told.
i know i just had the updated PCM flash, where the injectors cycle longer at shut off.
the pilot injection issue was a software change though...and folks
couldnt get it back once the software was updated by the dealer...
lots of folks complained that the trucks were a LOT smoother idling
w/ the PI as well...but again no one was told what the software
changes were...and most folks didnt even know they got reprogramed
(or flashed) it WELL after the fact.
Mines running find & ive not recvd any TSB's (since the ebpv & trans
fixes) so 'far as know theres no REAL reason for me to go in & get
flashed (for injector cycling)
if it aint broke im not fixin' it...and my fear is the dealers dont know
much of what theyre doin & theyll either break something or wanna
try and charge me for something.