[2eyefishclaw]

Its not a dealer problem its an Isuzu problem they provide info for the parts dept. they are all a buch of dummies who push buttons and pull parts if no one tells them that the 98 model sending unit fits the 04 pump they will never know.
now I am an Isuzu tech and if the sending unit on a 98 model is replaced and the PCM still has te old calibration and has never been ubdated then yes it will need to be done.....
99-04 never need programing
remember if replacing the sender on a late model 00-04 model you will need to purchase a fuel pump seal the one in the box is an o-ring and may not fit your tank
or easy way to remember if your tank is secured by 4 bolts you dont need to purchase the seal because you will use the blue o-ring that comes with the sender kit