What I'm getting at is...

Could I use a 2003 computer in my 2006 truck to help with tuning issues when converting to a return style fuel system. Are the 2003 computers fly by wire?

 

I just replaced my 03 with an 04 pcm and had it reflashed to a stock 03 file to make sure it started. Next, a crank relearn was done and then it was reprogrammed to a performance tune. All this was done using EFI Live (has built-in crank relearn procedure). Beyond 04, I could not tell you.

 

Why would you go from an 03 to an 04.

 

Superchips crapped out on me while programming. I needed to get one quickly and as inexpensive as possible. Local tuner was able to find an 04 from a fellow tuner and had it shipped overnight.

 

I know this post really don't help. but I have tuned a 04 truck with a 05 ECM and a 05 tune. There are few codes I can't clear (other modules on the truck that are different.) so the BATT light stays on all the time. but the truck runs fine.