Please read about hp programs
if its having an issue..its either a sensor going bad, and possibly the code was turned off from reporting an error, or you have a mechanical issue....
from what you are saying...it sounds like you might have a fuel pressure issue,,,which may be the fuel pump going bad.
stock GM fuel pressure is 58psi...4bar...
its not the program...guarantee that...
it can only change if you, or a another human being physically changes it using tuning software and connects to the car with a computer(or other hand held tuner device) in their hand.
requires key on, and a physical device connected to the car with a physical cable to make changes to the tune.





