hi i had bought a used hypertech programmer and when i plugged it in it downloaded info from the old truck on mine!! I have a 2000 and now the hypertech says it is a 99 with the wrong info. now my overhead display for mileage does not work anymore. and sometimes when i start it up the voltage gauge will drop to 8 and check gauge light will come on. checked this manually and it reads 14.8 which should be ok. after it runs for a few seconds volts come back up light goes off good to go. truck runs great yet but concerned if and what i need to do, if this a serious prob. or not? i can live w/o the overhead display.

 

Check with hypertech and see if programmming is same from the 99 and 2000. Many are year specific.