Aguayo was nominated by Alarcón and selected by the National Congress to replace Rosalía Arteaga upon her resignation in late March 1998.
His four-month tenure was described as a "total turn" and a departure in relations between the heads of the executive branch after the tense first year between Alarcón and Arteaga.
[4] The new VP gained support among various political, social, and business sectors that even came to call for the increasingly unpopular Alarcón to resign so that Aguayo could assume the Presidency.
[6] Aguayo reportedly cared for the rehabilitation of the provinces affected by El Niño and achieved the auspices of the United Nations to carry out a study on the phenomenon's impact, meant for the newly elected authorities to continue total reconstruction.
Finally, he was involved in the preparation of a transition team that also contacted the newly-elected government of Jamil Mahuad and his running mate, Gustavo Noboa, to inform them about ongoing and pending plans.