Resetting is usually a good idea after any mod. It lets the engine start at factory base numbers and then it learns from there. Once you've given it a few key cycles to relearn what normal is, it's a good idea to use a scan tool and check for codes and any other information your tool provides. On the OBDI ECMs you check the Vf voltage to see how much the ECM trimmed your fuel to bring it into "normal". Some of the OBDII ECMs also have a Vf terminal, but I haven't looked on the tC. Then you've got some idea what really happened when you did the mod.