this is a tried and true method for clearing non active codes on the alfa romeo giulia and stelvio.

non active codes and check engine lights mean you have a check engine light from a condition that has since been fixed.

an example of this is after you replace a dead battery or after hooking up your battery when disconnecting during a service. the dead battery or kack of battery connection condition that causes the check engine light is no longer present so you can use this method to clear the code.

another example would be if you had a brief overboost or under boost condition that causes a check engine light but you rectified the cause. this will work to clear the code.

it will not clear codes for conditions that ate still present and causing the check engine light.