I am having a problem after upgrading to 7.5 from 7.3 using a V1. Car was tuned on 7.3 and after upgrading I read the PCM data into 7.5 with a different computer and the car ran poorly afterwards. poor idle ect. I did the same thing with reading the PCM again with 7.3 and the car ran flawless. To make things interesting I did the same thing with my cousins car and his did the same exact thing. Ran poorly after the reading with 7.5 and ran fine after reading with 7.3. Neither car was written to so why would this make the car run differently? My cousins car was originally tuned using HP tuners where mine was tuned using 7.3

Thoughts?