Stamp 4 holder , driving via Northern Ireland

Hi All,
I’m stamp 4 holder based in Dublin . For my work reasons sometime I have to travel to Letterkenny , although Letterkenny is part of Republic of Ireland , however the route from Dublin to Letterkenny passes through Northern Ireland.

Would be any issues if I’m driving from one Irish City (Dublin) to another Irish City (Letterkenny) but some part of road journey goes through Northern Ireland

Legally you can't go through NI and you should go via Sligo. You're driving in and out another country that you have no right to be in. However, NI officers might as well let it slide, even if they stop you, which in itself is not usual occurrence.

Chance of repercussions is low, but it still could happen. Up to you to decide if you wish to take the risk.