The galaxy as all other cars use a KAM, or Keep Alive Memory circuit, most will have a separate FUSE for this one circuit.
This holds all the refined running adjustments and the memory, so pull this to clear it, this has the added advantage of clearing a wrong learnt value due to a dodgy sensor.
Having a fault code will NOT alter emissions as it works from the base map when there is a change due to sensor change.
It MAY not even have flagged a fault code anyway, unless way out of sync, if it was still within running parameters no fault will have been detected, this is the problem with ECU fault reporting, and the dire lack of diagnostic skills taught these days.
If there is no fuse marked KAM, then just disconnect the battery for 5 minutes is plenty.
tabetha