Sorry I'm just getting back to this. I just completed the swap a couple of days ago. Just had no time to begin. Anyway, I don't know why some are saying that only 03 DIC's will work in 03 cars, not true (almost). Following the various guides on here and other sites, it was easy...and it works! The only thing is that I think its not accurate. It's showing I'm getting 13 mpg on the freeway with no traffic sometimes, or my range is like 150 miles for a full tank of gas sometimes. Possible something else maybe wrong so when I get some free time ill check it out.
Select the AVG MPG on the display and then Press and hold the RESET for about 5 Seconds when cruising, Let it re aquire the average. It pulled some of the old data off of the ECU 13 MPG X 12 Gallon tank = 156 Miles.
99 Grand Prix SE-Blue CAI, 3.03 GR Transmission, U Bend Delete.
time to call the exterminator